Original data and independent reporting for the HVAC trade

Author: The HVAC Brief Editorial Team

  • Furnace Blower Motor: Symptoms, PSC vs ECM, Replacement

    Furnace Blower Motor: Symptoms, PSC vs ECM, Replacement

    Last reviewed: September 2026 · By the HVAC Brief Editorial Team · Our sourcing and editorial standards

    The short answer

    The blower motor moves all the air in a ducted system, in both heating and cooling, so when it fails nothing works. The usual symptoms are no airflow at the registers, airflow that weakens over time, a burning smell, or a furnace that heats then shuts down on its limit switch.

    Since July 3, 2019, federal standards have set a fan energy rating for residential furnace fans, which is why new equipment increasingly uses electronically commutated motors rather than the older permanent split capacitor type.

    What the blower actually does

    One motor serves the whole ducted system. In heating it pushes air across the furnace heat exchanger; in cooling it pulls return air across the evaporator coil. Airflow is also what protects the equipment: too little, and the furnace overheats or the coil freezes.

    That is why a blower problem looks like a dozen other problems. A furnace that shuts off on the limit switch and an air conditioner icing up can both be the blower, or the ducts feeding it. See why an AC freezes up.

    PSC and ECM motors

    There are two families in residential equipment, and they fail and cost differently.

    Factor PSC (permanent split capacitor) ECM (electronically commutated)
    Speed Fixed taps Variable, electronically controlled
    Electricity use Higher Substantially lower at part load
    Needs a capacitor Yes No
    Failure mode Bearings, windings, or the capacitor Motor module or control electronics
    Behaviour in high static pressure Moves less air, quietly under-performs Works harder to hold airflow, drawing more power

    The last row matters for diagnosis. An ECM will mask a duct problem by ramping up until it cannot, so the first sign is often a motor failure rather than poor airflow. Fixing the motor without fixing the duct restriction buys the next motor a short life.

    The federal rule behind ECM adoption

    Under 10 CFR 430.32(y), residential furnace fans manufactured on and after July 3, 2019 must meet a fan energy rating expressed in watts per 1,000 cfm, set by formula for each product class. For a non-weatherized, non-condensing gas furnace fan the requirement is FER = 0.044 multiplied by maximum airflow, plus 182.

    It is a fan power standard rather than a technology mandate, but meeting it pushed manufacturers toward ECM and constant-torque motors. It is also the reason a like-for-like motor swap on newer equipment is rarely a generic part.

    Capacitor first, motor second

    On a PSC blower, a failed run capacitor produces symptoms that look exactly like a failed motor: humming, slow starting, or no movement at all. The capacitor is the cheaper part and the more common failure, and it should be tested before any motor is quoted. See what a capacitor does and how it fails.

    Symptoms and what they usually mean

    Symptom Usually
    No air at any register, system otherwise running Motor, capacitor, or control board
    Airflow weaker than it used to be Filter, duct restriction, or a motor losing capacity
    Burning or hot electrical smell Motor overheating; shut it off
    Squealing or grinding on start Bearings
    Furnace heats, then shuts down repeatedly Airflow too low, tripping the limit switch
    Blower never stops Fan setting on, or a stuck relay or control board

    The last one is often not a fault at all. A thermostat fan setting left on “on” instead of “auto” runs the blower continuously, as explained in how thermostats work.

    What replacement costs

    No federal series measures HVAC repair prices, so we publish none. What is measured is the factory-gate trend for the motors themselves: the BLS producer price index for motor and generator manufacturing reached 318.1 in 2026-08, 47.5% above its 2019 average.

    Before authorising a motor replacement, ask three questions: was the capacitor tested, what was the static pressure, and is the replacement the same type as the original. Our guide to what HVAC repair costs are actually measured covers how to compare quotes when no price data exists.

    Frequently asked questions

    What are the signs of a failing blower motor?

    No air at the registers while the system runs, airflow that has weakened over time, squealing or grinding on start-up, a burning electrical smell, or a furnace that heats and then shuts down on its limit switch. On PSC motors, a failed capacitor causes the same symptoms and is cheaper to fix.

    What is the difference between PSC and ECM blower motors?

    A PSC motor runs at fixed speeds and needs a run capacitor; an ECM is electronically controlled, varies its speed and uses substantially less electricity at part load. Federal fan energy rating standards from July 3, 2019 pushed new equipment toward ECM designs.

    Can I replace a blower motor myself?

    It is not a beginner job. The blower sits on a 120 or 240 volt circuit, the assembly must be balanced when refitted, and the replacement has to match the original type and speed configuration. On PSC systems the capacitor should be tested first, since it is the cheaper and more common failure.

    Why did my blower motor fail early?

    Most often airflow restriction: a blocked filter, closed vents or undersized ductwork make the motor work harder and run hotter. Replacing the motor without measuring static pressure and fixing the restriction tends to shorten the new motor’s life too.

    Methodology and limitations

    Standards are quoted from 10 CFR 430.32(y). The motor price index is BLS series PCU335312335312, not seasonally adjusted, which covers motors broadly rather than HVAC replacement parts.

    • No federal source measures blower motor failure rates or replacement prices.
    • Motor types and speed configurations vary by manufacturer.
    • Nothing here is electrical advice for a specific installation.

    Sources

    1. Code of Federal Regulations, 10 CFR 430.32(y), residential furnace fan standards.
    2. US Bureau of Labor Statistics, Producer Price Index series PCU335312335312, motor and generator manufacturing.

    The HVAC Brief is an independent trade publication. We do not sell equipment, take manufacturer advertising, or accept payment for placement in our research. Corrections welcome.

  • Smart Thermostat Installation: Wiring and Compatibility

    Smart Thermostat Installation: Wiring and Compatibility

    Last reviewed: September 2026 · By the HVAC Brief Editorial Team · Our sourcing and editorial standards

    The short answer

    Most smart thermostats need a C wire, a common wire that supplies continuous power, and that is the single thing that decides whether the install takes twenty minutes or needs an electrician.

    Adoption is still low. EIA’s residential survey counted 12.78 million US homes with a smart or internet-connected thermostat, against 52.59 million with a programmable one and 44.08 million with a non-programmable one.

    11.7%Of homes with a thermostat have a smart one
    C wireThe usual blocker on older wiring
    Field dataWhat ENERGY STAR certification is based on
    44.1MHomes still on a non-programmable thermostat

    The C wire question

    A conventional thermostat is a switch: it closes a circuit to call for heat or cooling, and it needs no power of its own. A smart thermostat runs a screen and a radio continuously, so it needs a constant supply, which is what the C, or common, wire provides.

    1. Check what is behind the current thermostat. Turn the power off at the breaker, pull the thermostat off its plate, and photograph the wires and their terminal letters.
    2. Look for a wire on C. Sometimes an unused wire is tucked into the wall cavity, which is the easiest fix of all.
    3. If there is no C wire, the options are a power-extender kit supplied with many thermostats, running a new cable, or choosing a model designed to work without one.
    4. Note the system type. Heat pump wiring differs from a furnace and air conditioner, and dual fuel systems need a thermostat that can switch between them.

    Compatibility, beyond the C wire

    System Usually compatible What to watch
    Gas or oil furnace with central air Yes Needs a C wire or a power extender
    Heat pump with auxiliary heat Yes, with the right model Must control reversing valve and auxiliary or emergency heat
    Dual fuel, heat pump plus furnace Only specific models Needs a switchover setting, not a generic setup
    Line voltage electric baseboard No, in most cases Requires a line voltage model, 120 or 240 volts
    Millivolt or proprietary systems Often not Check manufacturer compatibility before buying

    ENERGY STAR’s own guidance is short and correct: “Make sure the smart thermostat you purchase is compatible with your heating and cooling system.” Our explainer on how thermostats work covers the control logic underneath.

    What a thermostat cannot do

    A smart thermostat changes when the system runs, not how well it runs. It cannot make a single-stage furnace modulate, fix duct leakage, or compensate for an oversized system. On a heat pump, a badly configured one can run expensive auxiliary heat more than necessary; see heat pump faults and normal behaviour. Zoning, not scheduling, is what fixes uneven rooms: see zoning systems.

    Does it save money?

    ENERGY STAR states that “Smart thermostats that earn the ENERGY STAR label have been independently certified, based on actual field data, to deliver energy savings.” That certification is a real, evidence-based bar, and it is product-level rather than a promise about your house.

    We publish no savings percentage, because the outcome depends on your schedule, your setpoints and your equipment. The mechanism is simple: savings come from the system running less, so a household that already sets back overnight has less to gain than one that never touches the dial. That is also why the 44.08 million homes on non-programmable thermostats have the most to gain.

    Installing one safely

    • Kill the power at the breaker, not just at the thermostat.
    • Photograph the existing wiring before disconnecting anything, and label wires by terminal, not by colour, because colour conventions are not reliable.
    • Do not let wires fall into the wall. Clip them or tape them to the wall while you work.
    • Set the system type correctly during setup: conventional, heat pump, or dual fuel. This is the most common configuration error.
    • Test both modes before you finish, and on a heat pump confirm auxiliary heat only comes on when it should.

    Frequently asked questions

    Do I need a C wire for a smart thermostat?

    Most need continuous power, which the C or common wire supplies. If there is no C wire, options are a power-extender kit included with many models, running new cable, or buying a model designed to work without one. Check behind the existing thermostat first, because an unused wire is often tucked into the wall.

    Will a smart thermostat work with my system?

    Conventional furnace and central air systems are usually straightforward. Heat pumps need a model that controls the reversing valve and auxiliary heat, dual fuel systems need specific models, and line voltage electric baseboard needs a line voltage thermostat. ENERGY STAR advises confirming compatibility before you buy.

    Do smart thermostats actually save energy?

    ENERGY STAR certifies models based on actual field data showing energy savings. How much you save depends on your schedule and setpoints, since savings come from the system running less. Households that never set back their temperature have the most to gain.

    How common are smart thermostats?

    EIA’s residential survey counted 12.78 million US homes with a smart or internet-connected thermostat, 11.7% of the 109.45 million homes that have a thermostat at all. Programmable models were in 52.59 million homes.

    Methodology and limitations

    Household thermostat counts are EIA RECS 2020 table HC6.1. Certification statements are quoted from ENERGY STAR. Wiring guidance is general; the equipment manufacturer’s instructions govern.

    • We publish no savings percentage, because results depend on household behaviour.
    • RECS 2020 remains the current vintage for equipment data; the 2024 survey’s heating and cooling tables are due in spring 2027 See what the 2024 survey release covers.; smart thermostat adoption has likely risen since.
    • Low voltage thermostat work is generally owner-accessible, but system wiring varies and errors can damage equipment.

    Sources

    1. US Energy Information Administration, Residential Energy Consumption Survey 2020, table HC6.1.
    2. ENERGY STAR, Smart Thermostats.

    The HVAC Brief is an independent trade publication. We do not sell equipment, take manufacturer advertising, or accept payment for placement in our research. Corrections welcome.

  • Whole House Humidifiers: What They Do and When They Help

    Whole House Humidifiers: What They Do and When They Help

    Last reviewed: September 2026 · By the HVAC Brief Editorial Team · Our sourcing and editorial standards

    The short answer

    A whole-house humidifier adds moisture to the air moving through your ductwork, to hold indoor humidity in the range EPA recommends. EPA advises that indoor relative humidity “should be kept below 60 percent” and “ideally between 30 percent and 50 percent, if possible.”

    It solves a winter problem with a physical cause. Cold outdoor air holds very little moisture, and once heated indoors its relative humidity falls, which is why houses feel dry in January and not in July.

    30 to 50%EPA’s ideal indoor relative humidity range
    60%The level EPA says to stay below
    3Common types: bypass, fan-powered and steam
    1Maintenance item most owners forget: the water panel

    Why indoor air goes dry in winter

    Relative humidity is relative to temperature. Cold air holds little water vapour, so when outdoor air at freezing enters a house and is heated to room temperature, its relative humidity collapses even though the absolute amount of moisture has not changed.

    The leakier the house, the worse it gets, because more of that cold, dry air is being brought in and heated. Sealing and insulating reduce the problem at source; see why envelope work comes first.

    The three types

    Type How it works Trade-offs
    Bypass Diverts warm supply air across a wet panel and back into the return Simple and cheap; needs the furnace blower running; uses a bypass duct
    Fan-powered Has its own fan to push air across the panel No bypass duct, more output; needs power
    Steam Boils water and injects steam into the duct Highest output, independent of furnace heat; uses the most electricity

    All three connect to a water line and a drain, and all three are controlled by a humidistat, which measures humidity the way a thermostat measures temperature. See how thermostats work for the control logic.

    Too much humidity is the bigger risk

    Over-humidifying in winter causes condensation on cold surfaces, starting with windows and ending inside wall cavities, and EPA’s guidance is explicit that indoor relative humidity should stay below 60%. If the windows are streaming, the humidifier is set too high. Our page on a house that is cold but humid covers the opposite failure.

    Maintenance, which is the whole game

    A neglected humidifier is worse than none, because it is a warm wet surface in the air path.

    1. Replace the water panel or pad at least once a heating season, more in hard water.
    2. Check the drain for blockage, and confirm water is actually leaving.
    3. Shut the water off in spring and close the damper on bypass models, or it will run through the cooling season.
    4. Watch the humidistat setting as outdoor temperature drops. The colder it gets outside, the lower the indoor setting has to be to avoid condensation.

    What it will not fix

    A humidifier will not fix a draughty house, a dusty one, or a duct system that cannot move air. Adding moisture to air that is not circulating produces damp in one room and dry air in another. If airflow is the underlying issue, see ductwork and airflow and how filters affect airflow.

    No federal source measures health outcomes or energy savings from whole-house humidifiers, and we publish neither.

    Frequently asked questions

    What humidity should a house be in winter?

    EPA advises keeping indoor relative humidity below 60 percent, ideally between 30 and 50 percent. In very cold weather the practical setting is at the lower end, because higher indoor humidity condenses on cold windows and inside wall cavities.

    Is a whole-house humidifier worth it?

    It addresses a real physical cause: heated winter air has low relative humidity. Whether it is worth the install and the annual maintenance depends on how dry your house actually gets, which a hygrometer will tell you for a few dollars. No federal source measures health or energy benefits.

    What maintenance does a humidifier need?

    Replace the water panel or pad at least once a heating season, keep the drain clear, and shut the water off and close the bypass damper in spring. A neglected unit is a wet surface sitting in the air path.

    Can a humidifier cause mould?

    Over-humidifying can, by producing condensation on cold surfaces and inside wall cavities. EPA’s guidance to stay below 60 percent relative humidity exists for that reason. Streaming windows are the visible warning that the setting is too high.

    Methodology and limitations

    Humidity guidance is quoted from EPA’s mould course materials. Equipment descriptions are general to residential ducted systems.

    • No federal source measures health outcomes, comfort or energy savings from whole-house humidification.
    • We publish no installed prices, because none is federally measured.
    • Correct settings vary with outdoor temperature and window construction.

    Sources

    1. US Environmental Protection Agency, Mold Course, Chapter 2, indoor relative humidity guidance.

    The HVAC Brief is an independent trade publication. We do not sell equipment, take manufacturer advertising, or accept payment for placement in our research. Corrections welcome.

  • Boiler Replacement: Efficiency Floors, Venting and Sizing

    Boiler Replacement: Efficiency Floors, Venting and Sizing

    Last reviewed: September 2026 · By the HVAC Brief Editorial Team · Our sourcing and editorial standards

    The short answer

    A new gas hot water boiler must reach at least 84% AFUE and an oil hot water boiler 86%, under 10 CFR 430.32(e). Those floors have applied to units manufactured on and after January 15, 2021, and they come with design requirements: no constant-burning pilot on gas, and automatic water temperature control on most classes.

    The bigger decision is condensing or not, because that changes the venting, the condensate drain and the water temperature the system must run at to deliver the efficiency on the label.

    84%Minimum AFUE, gas-fired hot water boiler
    86%Minimum AFUE, oil-fired hot water boiler
    9.29MUS homes heated mainly by a steam or hot water system
    $17.92Cost per million Btu from an 84% gas boiler, 2025/26 prices

    Federal minimums by boiler type

    The standards apply by product class, and the design requirements attached to them matter as much as the efficiency figure.

    Boiler class Minimum AFUE Design requirements
    Gas-fired hot water boiler 84% Constant-burning pilot not permitted; automatic means for adjusting water temperature required
    Gas-fired steam boiler 82% Constant-burning pilot not permitted
    Oil-fired hot water boiler 86% Automatic means for adjusting temperature required
    Oil-fired steam boiler 85% None
    Electric hot water boiler No AFUE minimum Automatic means for adjusting temperature required
    Electric steam boiler No AFUE minimum None

    Standby and off-mode power are also capped, at 9 watts for gas hot water boilers and 11 watts for oil. The standards attach to the date the boiler was manufactured, not to when it is installed.

    Condensing or non-condensing

    This is the choice that drives the rest of the job. A condensing boiler extracts heat from the flue gases until water vapour condenses, which is where the extra efficiency comes from.

    Factor Non-condensing Condensing
    Typical efficiency At or near the federal floor Above it, up to the mid 90s
    Venting Chimney or flue Plastic pipe, often through a side wall
    Condensate None Acidic condensate needs a drain and often neutralising
    Return water temperature Not critical Must stay low enough to condense, or the efficiency is not realised
    Best suited to Existing high temperature radiators Radiant floors and low temperature emitters

    The last row is the one that gets missed. A condensing boiler connected to old cast iron radiators run at high water temperature will not condense much of the time, so it will not deliver its rated efficiency. Our page on radiant floor heating covers the low temperature case where condensing boilers do their best work.

    Orphaned water heater

    If the old boiler shared a chimney with an atmospheric water heater, replacing it with a sidewall-vented condensing boiler leaves that water heater venting alone into an oversized, now cold chimney. That can cause poor draft and condensation inside the flue. It has to be dealt with in the same job, usually by relining the chimney or changing the water heater. The same problem arrives with the 95% AFUE furnace standard in 2028.

    Sizing, and why bigger is worse

    Boilers are commonly replaced like for like, which repeats whatever oversizing the original install had. An oversized boiler short cycles: it satisfies the thermostat quickly, shuts down, and starts again, which wastes fuel and wears the burner.

    A heat loss calculation for the building is the correct basis, the boiler equivalent of a Manual J load calculation. Ask for it, and ask what the radiator or emitter output is at the water temperature the new boiler will actually run.

    What it costs to run

    At 2025/26 heating season average prices and federal minimum efficiencies, heat from an 84% gas boiler cost about $17.92 per million Btu delivered, against $33.68 from an 86% oil boiler.

    Fuel price dominates that comparison, not the few points of efficiency between classes. The full table, including heat pumps and electric resistance, is in what heat costs by fuel. For how boiler systems distribute that heat, see boilers and baseboard heating.

    What to ask before signing

    • What heat loss calculation was done, and what output did it give?
    • Condensing or not, and if condensing, what return water temperature will the system run at?
    • Where does the flue terminate, and what happens to anything else on the old chimney?
    • Where does the condensate drain, and does it need neutralising?
    • What is the AFUE of the specific model, and what is its standby power?

    Our contractor checklist covers the licence, permit and warranty side of the same conversation.

    Frequently asked questions

    What AFUE does a new boiler need?

    At least 84% for a gas-fired hot water boiler, 82% for a gas steam boiler, 86% for an oil-fired hot water boiler and 85% for an oil steam boiler, for units manufactured on and after January 15, 2021, under 10 CFR 430.32(e). Electric boilers have no AFUE minimum.

    Is a condensing boiler worth it?

    Only if the system can run at a low enough return water temperature to condense. Paired with radiant floors or generously sized low temperature emitters it delivers its rated efficiency; connected to old high temperature radiators it often will not. It also needs plastic venting and an acidic condensate drain.

    What size boiler do I need?

    Size it on a heat loss calculation for the building, not on the output of the boiler being replaced. Like-for-like replacement repeats any oversizing in the original installation, and an oversized boiler short cycles, which wastes fuel and wears the burner.

    How much does a boiler cost to run?

    At 2025/26 season average fuel prices and federal minimum efficiency, about $17.92 per million Btu of delivered heat from a gas hot water boiler and $33.68 from an oil one. Fuel price matters far more than the efficiency difference between classes.

    Methodology and limitations

    Efficiency and design requirements are quoted from 10 CFR 430.32(e)(2). Household counts are EIA RECS 2020 table HC6.1. Running costs come from our fuel cost page, which uses EIA season average prices and federal minimum efficiencies.

    • Standards apply to manufacture date, not installation date.
    • We publish no installed prices, because no federal series measures them.
    • Heat loss calculation procedures are private industry standards, which we name but do not reproduce.

    Sources

    1. Code of Federal Regulations, 10 CFR 430.32(e)(2), residential boiler standards.
    2. US Energy Information Administration, Residential Energy Consumption Survey 2020, table HC6.1.

    The HVAC Brief is an independent trade publication. We do not sell equipment, take manufacturer advertising, or accept payment for placement in our research. Corrections welcome.

  • Water Heater Replacement: Sizing, Fuel and the 2029 Rules

    Water Heater Replacement: Sizing, Fuel and the 2029 Rules

    Last reviewed: September 2026 · By the HVAC Brief Editorial Team · Our sourcing and editorial standards

    The short answer

    Replacing a water heater comes down to three decisions: fuel, capacity and whether to move to a heat pump water heater. Federal minimum efficiency is set by formula, not by a single number, and it changes for units manufactured on or after May 6, 2029.

    One rule that does not apply: the tougher standard for gas tankless water heaters. Congress disapproved it, and the Department of Energy formally withdrew the rule on May 20, 2025.

    May 6, 2029New federal minimums apply to storage water heaters manufactured from this date
    WithdrawnThe 2024 gas tankless standard, disapproved by Congress
    -5.2%Electric storage shipments, year to date through July
    >1.0The UEF level that only a heat pump water heater can reach

    How federal efficiency rules work here

    Water heaters are rated by Uniform Energy Factor, and the minimum is a formula rather than a fixed figure. It varies by product class, storage volume and draw pattern, which is why any page quoting “the minimum UEF” has quietly fixed all three.

    Under 10 CFR 430.32(d), a gas-fired storage water heater between 20 and 55 gallons on a medium draw pattern must reach a UEF of 0.6483 minus 0.0017 times the rated volume. A 50 gallon unit therefore needs about 0.563. The equivalent electric storage class needs 0.9307 minus 0.0002 times volume, about 0.921.

    Class (medium draw) Formula, before May 6, 2029 At 50 gallons
    Gas-fired storage, 20 to 55 gal 0.6483 − (0.0017 × volume) 0.563
    Electric storage, 20 to 55 gal 0.9307 − (0.0002 × volume) 0.921
    Oil-fired storage, up to 50 gal 0.6078 − (0.0016 × volume) 0.528
    Electric storage, over 55 gal 2.1171 − (0.0011 × volume) 2.029 at 80 gal

    That last row is the important one. A UEF above 1.0 means the appliance delivers more energy than it consumes, which resistance elements cannot do. The large electric classes are effectively heat pump water heaters by regulation.

    What changes in 2029

    A second table in the same section applies to units manufactured on or after May 6, 2029, and it is based on effective storage volume rather than rated volume. It also adds classes below 20 gallons and above 100 gallons that the current table does not cover.

    This affects manufacture date, not your installation. A compliant heater built before that date remains legal to sell and install afterwards, the same principle that governs SEER2 minimums for cooling equipment.

    The tankless rule that was cancelled

    DOE published amended standards for consumer gas-fired instantaneous water heaters on December 26, 2024 (89 FR 105188), with an effective date of March 11, 2025. The effective date was delayed twice, and on May 20, 2025 DOE withdrew the rule entirely (90 FR 21390), stating it was acting “Pursuant to the Congressional Review Act” to withdraw “a disapproved final rule”. Gas tankless water heaters are therefore still governed by the earlier standard, and any page describing a new tankless minimum is out of date.

    Sizing: first hour rating, not gallons

    Tank size is the number everyone quotes and the wrong one to buy on. The useful figure is the first hour rating, how much hot water the unit can deliver in the busiest hour, which combines tank volume with recovery rate.

    1. Work out your peak hour, usually a morning: showers, a dishwasher, a laundry load.
    2. Add the demand in gallons for that hour.
    3. Match the first hour rating to that figure, not to the tank size of the old unit.
    4. For tankless, the equivalent is flow in gallons per minute at your incoming water temperature. Cold inlet water cuts deliverable flow, so a unit sized for a southern climate underperforms in a northern one.

    A heat pump water heater has a further constraint: it needs air volume and clearance around it, and it cools and dehumidifies the space it sits in.

    Fuel cost, honestly

    Water heating cost follows the same fuel prices as space heating. At 2025/26 season averages, natural gas cost about $15.05 per million Btu of fuel against about $52.10 for electricity.

    That gap is why gas has been cheaper to run, and why a heat pump water heater changes the comparison: by moving heat rather than making it, it uses a fraction of the electricity a resistance element does. Our page on what heat costs by fuel sets out the arithmetic and the assumptions behind it.

    What the market is doing

    Shipments are falling on both fuels. Through July 2026, gas storage water heater shipments were 2,487,389 units, down 2.5% on 2025, and electric storage was 2,877,192, down 5.2%.

    Electric is also down 5.5% against the same period of 2024, so this is a two-year decline rather than one soft season. More in our water heater shipments and standards report.

    Frequently asked questions

    What size water heater do I need?

    Match the first hour rating to your peak hour demand rather than matching the old tank’s gallon size. Add up the hot water used in your busiest hour, usually a morning, and buy to that figure. For tankless, size on gallons per minute at your winter incoming water temperature.

    Are there new federal water heater standards?

    Yes for storage water heaters: a new table of minimum Uniform Energy Factors applies to units manufactured on or after May 6, 2029, under 10 CFR 430.32(d). For gas tankless there is no new standard: DOE’s December 2024 rule was disapproved by Congress and withdrawn on May 20, 2025.

    Is a heat pump water heater worth it?

    It uses far less electricity than a resistance element because it moves heat rather than generating it, which is why federal minimums for the larger electric classes require a UEF above 1.0, a level only a heat pump can reach. It needs clearance and air volume, and it cools the space it occupies. No federal source publishes installed costs, so we do not quote a payback.

    Gas or electric water heater?

    On fuel price alone gas has been cheaper: about $15.05 per million Btu against $52.10 for electricity at 2025/26 season averages. A heat pump water heater narrows or closes that gap by using a fraction of the electricity. Venting, existing connections and local prices decide the rest.

    Methodology and limitations

    Efficiency requirements are quoted from 10 CFR 430.32(d). Rulemaking history is from Federal Register documents 89 FR 105188, 90 FR 9951, 90 FR 13054 and 90 FR 21390. Shipments are AHRI’s July 2026 release. Fuel prices are EIA season averages as documented on our fuel cost page.

    • Worked UEF examples assume a medium draw pattern; other draw patterns have different formulas.
    • Standards apply to manufacture date, not installation date.
    • We publish no installed prices or payback periods, because no federal series measures them.

    Sources

    1. Code of Federal Regulations, 10 CFR 430.32(d), water heater energy conservation standards.
    2. US Department of Energy, “Energy Conservation Standards for Consumer Gas-Fired Instantaneous Water Heaters”, final rule 89 FR 105188 (December 26, 2024) and final rule; withdrawal, 90 FR 21390 (May 20, 2025).
    3. Air-Conditioning, Heating, and Refrigeration Institute, July 2026 shipment release.

    The HVAC Brief is an independent trade publication. We do not sell equipment, take manufacturer advertising, or accept payment for placement in our research. Corrections welcome.

  • HVAC Emergencies: What Counts and What to Do First

    HVAC Emergencies: What Counts and What to Do First

    Last reviewed: September 2026 · By the HVAC Brief Editorial Team · Our sourcing and editorial standards

    The short answer

    Three HVAC situations are genuine emergencies: a carbon monoxide alarm sounding, a gas smell, or any burning smell or smoke. In those, leaving the building comes before calling anyone.

    Everything else, including no heat in winter and no cooling in a heatwave, is urgent rather than dangerous for most households, and becomes an emergency when the temperature threatens vulnerable people or the building.

    Stop and leave: the three real emergencies

    These are not service calls in the ordinary sense. Get out first, then call from outside.

    1. A carbon monoxide alarm sounds. Get everyone outside into fresh air, then call the fire service or 911. Do not go back in to investigate. CPSC estimated 274 non-fire carbon monoxide deaths from consumer products in 2022, and 76 of them, 28%, involved heating systems.
    2. You smell gas. Do not operate switches or appliances. Leave, then call the gas utility’s emergency line from outside.
    3. Burning smell, smoke or soot. Shut the system off at the thermostat and the breaker if you can do it safely, then leave and call.

    CPSC’s guidance for the prevention side is a “yearly professional inspection of all fuel-burning home heating systems, including furnaces, boilers, fireplaces, wood stoves, water heaters, chimneys, flues and vents.”

    Urgent, but not an evacuation

    These justify an out-of-hours call, and they are what most emergency HVAC services actually attend.

    Situation Why it is urgent What to do first
    No heat, freezing outside Risk of burst pipes and cold exposure Check thermostat, breaker, filter, gas supply; keep taps trickling
    No cooling in extreme heat Heat illness, especially for older adults, infants, the ill Move to a cooler space, check breaker and filter, use fans
    Water pouring from the indoor unit Property damage Shut the system off, clear the condensate drain if accessible
    Electrical burning smell, no smoke Component overheating Shut off at the breaker, call
    Outdoor unit humming, not starting Motor can overheat Switch off at the thermostat; likely a capacitor or contactor

    That last one is one of the most common after-hours calls. See what a capacitor does and what HVAC noises mean.

    Check these before you pay an out-of-hours rate

    A meaningful share of emergency calls end in something the owner could have checked in two minutes.

    • Thermostat. Mode, setpoint, batteries, and whether it is calling for heat or cooling at all. See how thermostats work.
    • Breaker and outdoor disconnect. Reset a tripped breaker once. If it trips again, stop and call.
    • The filter. A blocked filter causes no-heat lockouts on the heating side and frozen coils on the cooling side. See why an AC freezes up.
    • The furnace door switch. A panel not seated will stop a furnace completely.
    • Gas supply. Other gas appliances working tells you the supply is on.

    If the furnace is trying to light and failing, the ignition sequence page explains what the pattern of clicks and pauses is telling you.

    What emergency rates actually buy

    Out-of-hours work is priced for the visit, not the fix. Parts availability at 2am is the real constraint, and many night calls end in a temporary measure with the repair completed the next working day. Ask what the call-out fee covers, whether it is credited against the repair, and whether the part is on the van, before agreeing to the visit.

    If you cannot get heat tonight

    Two safety points matter more than comfort, and both appear in CPSC’s heating guidance: never heat a home with a cooking appliance, and never run a generator or any engine-driven tool indoors or in an attached garage. Engine-driven tools were associated with the largest share of carbon monoxide deaths in CPSC’s 2022 estimates, 39% of the total, with generators the main contributor.

    Frequently asked questions

    What counts as an HVAC emergency?

    A sounding carbon monoxide alarm, a gas smell, or smoke and burning smells are true emergencies: leave the building first and call from outside. No heat in freezing weather, no cooling in extreme heat, and water damage are urgent and justify an out-of-hours call, but are not evacuations.

    What should I do if my heat goes out in winter?

    Check the thermostat mode and batteries, the breaker, the filter and the furnace door panel, and confirm other gas appliances work. Keep taps trickling to reduce the risk of frozen pipes. Never heat the house with a cooking appliance or run a generator indoors.

    Is no air conditioning an emergency?

    It can be, depending on who is in the house. Extreme heat is dangerous for older adults, infants and people with medical conditions. For most households it is urgent rather than an emergency: move to a cooler space, run fans, and check the breaker and filter first.

    Is emergency HVAC service more expensive?

    Generally yes, through an out-of-hours call-out fee. No federal source measures HVAC pricing. Ask what the fee covers, whether it is credited against the repair, and whether the likely part is on the van, since many night visits end in a temporary fix.

    Methodology and limitations

    Carbon monoxide figures are CPSC 2022 annual estimates, published May 2026. Safety guidance is quoted or summarised from CPSC’s home heating equipment materials.

    • We publish no emergency call-out prices, because no federal source measures them.
    • CPSC estimates cover consumer products under its jurisdiction and are revised in later reports.
    • This page is general guidance, not instructions for a specific appliance or a medical situation.

    Sources

    1. US Consumer Product Safety Commission, Home Heating Equipment.
    2. US Consumer Product Safety Commission, Non-Fire Carbon Monoxide Deaths Associated with the Use of Consumer Products, 2022 Annual Estimates, published May 2026.

    The HVAC Brief is an independent trade publication. We do not sell equipment, take manufacturer advertising, or accept payment for placement in our research. Corrections welcome.

  • HVAC Tune-Up: What a Real One Actually Includes

    HVAC Tune-Up: What a Real One Actually Includes

    Last reviewed: September 2026 · By the HVAC Brief Editorial Team · Our sourcing and editorial standards

    The short answer

    A real tune-up is a list of measurements and cleanings, not a visual inspection. ENERGY STAR’s maintenance checklist names nine contractor tasks, including tightening electrical connections and measuring voltage and current on motors, cleaning the coils, checking refrigerant level, and checking gas connections, burner combustion and the heat exchanger.

    No federal rule sets what a tune-up must include, so the word means whatever the company selling it decides. The checklist below is what to ask for.

    What ENERGY STAR says a contractor should do

    These nine items are the closest thing to a public standard for a maintenance visit, and they are the ones to hold a contractor to.

    Task Why
    Check thermostat settings to ensure the cooling and heating system keeps you comfortable when you are home and saves energy while you are away
    Tighten all electrical connections and measure voltage and current on motors
    Lubricate all moving parts to reduce friction in motors
    Check and inspect the condensate drain in your central air conditioner, furnace and/or heat pump
    Check controls of the system to ensure proper and safe operation
    Clean evaporator and condenser air conditioning coils because dirty coils make the system run longer
    Check the refrigerant level and adjust if necessary
    Clean and adjust blower components to provide proper system airflow
    Check all gas or oil connections, gas pressure, burner combustion and heat exchanger on the heating side

    ENERGY STAR also gives the timing: “Check the cooling system in the spring and the heating system in the fall”, and for owners, “Inspect, clean, or change air filters once a month in your central air conditioner, furnace, and/or heat pump.”

    The measurements to ask for in writing

    The difference between a real tune-up and a sticker on the furnace is whether numbers were recorded. Ask for these on the invoice.

    1. Refrigerant charge, verified by measurement. Superheat or subcooling, not “topped up”. A system that needs refrigerant has a leak; see what a recharge really means.
    2. Temperature rise or temperature split. The difference between return and supply air, compared with the range on the equipment data plate.
    3. Static pressure. The duct system’s resistance. High static pressure is the most commonly missed cause of poor performance and short equipment life. See ductwork and airflow.
    4. Motor amp draw. Compared with the nameplate rating, it shows a motor beginning to fail.
    5. Combustion readings on the heating side. On any gas or oil appliance, plus a check for spillage at the draft hood.
    What a tune-up is not

    It is not a duct cleaning, it is not a refrigerant top up, and it does not include parts. A visit that finds nothing wrong is a good outcome, not a wasted fee. If a tune-up always ends in a recommended repair, that is a sales pattern worth noticing, and our guide to choosing a contractor covers how to test it.

    Does maintenance actually pay?

    Honestly, the evidence is thinner than the marketing. No federal agency measures the return on a maintenance visit, and we do not publish a savings percentage because none is measured.

    What has a clear mechanism behind it is narrower: a clean filter and clean coils preserve airflow and heat transfer, a correct refrigerant charge keeps capacity where it was designed to be, and a combustion check is a safety measure with a documented hazard behind it. Our page on how often HVAC should be serviced sets out what is established and what is not.

    Maintenance plans

    Most plans bundle one or two visits a year with a discount on repairs and priority scheduling. Three questions decide whether one is worth it:

    • Does the plan list the tasks, or does it just promise a “precision tune-up”?
    • Is the discount on parts, labour, or both, and does it apply to the diagnostic fee?
    • Does it auto-renew, and what happens to unused visits?

    Frequently asked questions

    What is included in an HVAC tune-up?

    ENERGY STAR’s checklist names nine contractor tasks: checking thermostat settings, tightening electrical connections and measuring voltage and current on motors, lubricating moving parts, inspecting the condensate drain, checking system controls, cleaning evaporator and condenser coils, checking refrigerant level, cleaning and adjusting blower components, and checking gas or oil connections, gas pressure, burner combustion and the heat exchanger.

    Is an AC tune-up worth it?

    No federal source measures the savings, so treat percentage claims with caution. The defensible case is narrower: airflow, correct refrigerant charge and combustion safety all have clear mechanisms. Ask for recorded measurements, which is what separates a real visit from a visual check.

    How often should a tune-up be done?

    The common advice is annually, and twice a year for a heat pump because it runs in both seasons. ENERGY STAR suggests checking the cooling system in spring and the heating system in autumn. No federal rule sets an interval; manufacturer warranty terms often do.

    What should be on the invoice?

    Measured values, not just ticks: superheat or subcooling, temperature rise or split, static pressure, motor amp draws against nameplate, and combustion readings on gas or oil equipment. Without numbers there is nothing to compare against next year.

    Methodology and limitations

    Task list quoted from the ENERGY STAR maintenance checklist. Industry maintenance procedures are published privately by ACCA, which we name but do not reproduce.

    • No federal rule defines a tune-up or sets a service interval.
    • We publish no savings percentage, because no federal source measures one.
    • Required tasks vary by equipment type; a heat pump and an oil furnace do not need the same visit.

    Sources

    1. ENERGY STAR, Maintenance Checklist.
    2. Air Conditioning Contractors of America, maintenance standards, named as industry procedures.

    The HVAC Brief is an independent trade publication. We do not sell equipment, take manufacturer advertising, or accept payment for placement in our research. Corrections welcome.

  • Heat Pump Repair: The Faults Only Heat Pumps Have

    Heat Pump Repair: The Faults Only Heat Pumps Have

    Last reviewed: September 2026 · By the HVAC Brief Editorial Team · Our sourcing and editorial standards

    The short answer

    A heat pump has every failure an air conditioner has, plus four of its own: the reversing valve, the defrost control, the auxiliary heat strips and the outdoor coil freezing for reasons that are not a fault.

    That last one causes most unnecessary service calls. A heat pump that steams and drips in cold weather, or blows cool air for a few minutes, is usually running a normal defrost cycle.

    16.13MUS homes with a heat pump as main heating
    4Failure modes specific to heat pumps
    2Seasons of service a heat pump needs, because it runs year round
    $0Federal data on what any repair costs

    The faults that are specific to heat pumps

    These four have no equivalent on a cooling-only system, and they are where a general air conditioning diagnosis goes wrong.

    Part What it does What failure looks like
    Reversing valve Switches the refrigerant flow between heating and cooling System cools when it should heat, or gets stuck in one mode
    Defrost control board and sensor Runs a defrost cycle when the outdoor coil ices Coil stays iced over, or the unit defrosts constantly
    Auxiliary or emergency heat strips Electric resistance backup in very cold weather No backup heat, or strips running constantly and a very high bill
    Outdoor coil and base pan Absorbs heat from outdoor air in winter Ice building at the base, blocked drainage

    Normal behaviour that looks like a fault

    Heat pumps behave differently from furnaces, and three normal behaviours generate service calls.

    • Defrost cycles. In cold, damp weather the outdoor coil frosts. The unit periodically reverses to melt it, which produces steam, dripping and a few minutes of cooler air indoors. This is designed behaviour.
    • Cooler supply air. A heat pump delivers air cooler than a furnace does. It feels lukewarm at the register while still heating the house.
    • Long run times. Heat pumps are meant to run for long periods at low output. Short, fierce cycles are the problem, not long gentle ones.

    Our explainer on how a heat pump works covers the cycle these behaviours come from.

    The expensive mistake: leaving it on emergency heat

    Emergency heat bypasses the heat pump and runs electric resistance strips. That is the most expensive heat in the house. At 2025/26 season prices, resistance heat cost about $52 per million Btu against about $24 from a minimum-efficiency heat pump, more than double. Use it when the heat pump has failed, not as a cold weather setting. See what heat costs by fuel.

    The faults it shares with any air conditioner

    Everything in the refrigeration circuit and the electrical path fails the same way it does on a cooling-only system: capacitors, contactors, fan motors, compressors, and refrigerant leaks.

    A heat pump works the circuit harder, because it runs in both seasons rather than one. That is the argument for servicing it twice a year rather than once. See capacitor failures and what a tune-up should include.

    What repairs cost

    No federal series measures heat pump repair prices, and the range that matters most, a reversing valve or compressor replacement against the cost of a new system, is exactly the one nobody measures.

    Two questions make a quote comparable. What refrigerant does the system use, since an R-410A system faces a tightening supply under the phasedown schedule. And what was measured, in pressures and temperatures, to reach the diagnosis.

    Frequently asked questions

    Why is my heat pump blowing cold air?

    Most often it is a normal defrost cycle: the unit briefly reverses to melt frost off the outdoor coil, which produces cooler air indoors and steam outside for a few minutes. If it persists, suspect the reversing valve, a refrigerant charge problem or a defrost control fault.

    Why is my heat pump frozen or iced up?

    Light frost on the outdoor coil in cold, damp weather is normal and the defrost cycle clears it. Ice that stays, or builds at the base of the unit, points at a defrost control or sensor fault, blocked drainage, or low refrigerant charge.

    What is the most common heat pump repair?

    The same electrical wear parts as any air conditioner, chiefly capacitors and contactors, followed by defrost controls and sensors. Reversing valve and compressor failures are much less common and much more expensive.

    Should I use emergency heat?

    Only when the heat pump is not working. Emergency heat runs electric resistance strips, which at 2025/26 average prices cost roughly twice as much per unit of heat as a minimum-efficiency heat pump. Leaving it on is a common and expensive mistake.

    Methodology and limitations

    Component behaviour is described in general terms for residential air-source heat pumps. Household counts are EIA RECS 2020 table HC6.1. Running cost comparisons come from our fuel cost page, which uses EIA season average prices and federal minimum efficiencies.

    • No federal source measures repair prices or failure rates, and we publish neither.
    • Defrost behaviour varies by manufacturer and control strategy.
    • Nothing here is a diagnosis for a specific system.

    Sources

    1. US Energy Information Administration, Residential Energy Consumption Survey 2020, table HC6.1.
    2. Code of Federal Regulations, 10 CFR 430.32(c), heat pump efficiency standards.

    The HVAC Brief is an independent trade publication. We do not sell equipment, take manufacturer advertising, or accept payment for placement in our research. Corrections welcome.

  • Furnace Repair: What Actually Fails, and What It Costs

    Furnace Repair: What Actually Fails, and What It Costs

    Last reviewed: September 2026 · By the HVAC Brief Editorial Team · Our sourcing and editorial standards

    The short answer

    Most furnace repairs come down to a short list of parts: the igniter, the flame sensor, the pressure switch, the blower motor and its capacitor, the limit switch and the control board. A cracked heat exchanger is the one failure that ends the furnace rather than starting a repair.

    No federal source publishes what any of these repairs cost, so every price range you find online is a vendor survey. What is documented is the safety side: CPSC estimates 76 deaths from carbon monoxide involving heating systems in 2022.

    What actually fails, by symptom

    Furnaces mostly fail in one of four ways, and each points at a different group of parts.

    Symptom Usual suspects Owner fixable
    No heat, no ignition attempt Thermostat, power, door switch, control board Check thermostat and breaker only
    Ignites then shuts down within seconds Flame sensor, dirty burners, flue blockage No
    Blower runs, air is cold Igniter, gas valve, pressure switch, limit switch No
    Short cycling Dirty filter, closed vents, oversized furnace, limit switch Filter and vents, yes
    Noise on start or run Blower motor, bearings, capacitor, inducer motor No
    Soot, burning smell, alarm sounding Combustion problem or heat exchanger Shut it off and call

    The single most common no-heat pattern is a furnace refusing to light because a safety interlock has not proved. Our page on why a furnace will not ignite walks the start sequence step by step.

    The parts that fail most

    These are wear items on a gas furnace. Each is cheap relative to the machine, and each stops the furnace completely.

    1. Hot surface igniter. A brittle ceramic element that glows to light the burners. It fails from age and from being touched.
    2. Flame sensor. A metal rod that proves a flame is present. It gets coated and stops conducting, so the furnace lights and immediately shuts down.
    3. Pressure switch. Confirms the inducer is drawing properly. A blocked flue or a cracked hose will keep it open, and the furnace will not fire.
    4. Capacitor. Starts and runs the blower motor. See what a capacitor does.
    5. Blower motor. Moves the heated air. See blower motor symptoms and types.
    6. Limit switch. Shuts the furnace down when it overheats, usually because airflow is restricted. A limit switch that trips repeatedly is reporting an airflow problem, not causing one.
    The one that ends the furnace

    A cracked heat exchanger lets combustion gases mix with the air you breathe. It is not repaired; the furnace is replaced or the exchanger is swapped if still under warranty. CPSC estimated 274 non-fire carbon monoxide deaths from consumer products in 2022, of which 76 (28%) involved heating systems, the second largest category after engine-driven tools. CPSC advises “a yearly professional inspection of all fuel-burning home heating systems, including furnaces, boilers, fireplaces, wood stoves, water heaters, chimneys, flues and vents.”

    Repair or replace

    Three things decide it, and age alone is not one of them.

    • What failed. An igniter or a capacitor is a routine repair. A heat exchanger, a control board on an old furnace, or a second major failure in a season pushes towards replacement.
    • What the furnace is. An 80% AFUE furnace replaced today can be a condensing model; from December 18, 2028 new non-weatherized gas furnaces must be 95% AFUE, which changes venting. See the 2028 standard.
    • Whether it is still safe. Combustion faults are not a cost question.

    Age is a weak signal on its own: 20.0% of US homes that heat are running main heating equipment 20 years old or more, and most of it works.

    What a furnace repair costs

    No federal series measures HVAC repair prices. BLS publishes producer prices for equipment and wages for the trade, but nothing that tells you what a flame sensor replacement costs in your town.

    What you can do is make quotes comparable: ask for the part and the labour separately, ask what failed and why, and ask what the technician measured. A part that fails twice in two seasons is a symptom of something else. Our page on what HVAC repair costs are actually measured explains the gap.

    How much furnace repair there is to do

    The installed base is large and old. A central warm-air furnace is the main heating equipment in 74.42 million US homes, 63.2% of homes that heat, and gas furnace shipments are running below last year, which means more of that base is being repaired rather than replaced.

    Frequently asked questions

    What is the most common furnace repair?

    Ignition-related parts: the hot surface igniter and the flame sensor. Both stop the furnace from producing heat, both are inexpensive parts, and both are routine replacements. Blower capacitors and pressure switches are the next most common.

    Is it worth repairing a furnace?

    Usually, unless the heat exchanger has failed, the same major component has failed twice, or a combustion fault has been found. What failed matters more than the furnace’s age. A furnace replaced now can also be affected by the 95% AFUE standard that applies to units manufactured from December 18, 2028.

    How much does furnace repair cost?

    No federal source measures it, so any published range is a vendor survey or contractor estimate rather than measured data. Ask for the part and labour separately, and ask what was measured to reach the diagnosis.

    Is a furnace problem dangerous?

    It can be. CPSC estimated 76 non-fire carbon monoxide deaths involving heating systems in 2022, 28% of the 274 consumer product CO deaths that year. If a CO alarm sounds, or you smell burning or see soot, shut the system off and get out before calling anyone.

    Methodology and limitations

    Component descriptions are general to residential gas furnaces. Carbon monoxide figures are CPSC 2022 annual estimates, published May 2026. Installed base is EIA RECS 2020 table HC6.1.

    • We publish no repair prices, because no federal series measures them.
    • CPSC estimates are for consumer products under its jurisdiction and are revised in later reports.
    • Nothing here is a substitute for a qualified technician inspecting your equipment.

    Sources

    1. US Consumer Product Safety Commission, Home Heating Equipment and Non-Fire Carbon Monoxide Deaths Associated with the Use of Consumer Products, 2022 Annual Estimates (May 2026).
    2. US Energy Information Administration, Residential Energy Consumption Survey 2020, table HC6.1.
    3. Code of Federal Regulations, 10 CFR 430.32(e), furnace efficiency standards.

    The HVAC Brief is an independent trade publication. We do not sell equipment, take manufacturer advertising, or accept payment for placement in our research. Corrections welcome.

  • Heat Pumps Were 45% of July HVAC Shipments

    Heat Pumps Were 45% of July HVAC Shipments

    Last reviewed: September 2026 · By the HVAC Brief Editorial Team · Our sourcing and editorial standards

    The short answer

    Heat pumps were 45.1% of the central air conditioners and heat pumps shipped in the US in July 2026, and combined shipments rose 20.1% on July 2025 to 916,830 units, according to AHRI’s July statistical release, published September 11, 2026.

    The year-to-date picture is the one worth keeping. Through July, the industry has shipped 126,433 fewer air conditioners and heat pumps than in the same period of 2024, but 142,854 more heat pumps. The category is converting rather than growing.

    45.1%Heat pump share of July shipments
    +20.1%Combined AC and heat pump shipments vs July 2025
    -5.1%Gas furnace shipments, year to date
    45.6%Heat pump share year to date, from 42.1% in 2024

    July shipments

    Every cooling category rose against a weak July 2025, with air conditioners up 22.3% and heat pumps up 17.6%. Both remain below July 2024.

    July shipments 2026 2025 Change 2024
    Air conditioners 503,151 411,530 +22.3% 613,216
    Air-source heat pumps 413,679 351,913 +17.6% 430,204
    Combined 916,830 763,443 +20.1% 1,043,420
    Gas warm air furnaces 265,810 260,224 +2.1% n/a
    Oil warm air furnaces 2,681 1,963 +36.6% n/a

    A 20.1% monthly gain looks dramatic in isolation. Against July 2024 the same month is down 12.1%, which is why we publish the two-year column.

    The two-year comparison, which is the story

    Year to date through July, heat pumps are 142,854 units ahead of 2024 while air conditioners are 269,287 units behind. Net, the combined category is 126,433 units smaller than two years ago.

    Year to date, January to July 2026 2025 2024 2026 vs 2024
    Air conditioners 3,063,290 2,911,784 3,332,577 -269,287
    Air-source heat pumps 2,570,228 2,428,800 2,427,374 +142,854
    Combined 5,633,518 5,340,584 5,759,951 -126,433
    Heat pump share 45.6% 45.5% 42.1% +3.5 pts

    Heat pump share has moved 3.5 percentage points in two years, and almost all of that came from air conditioners rather than from a larger market. We tracked the same pattern in the heat pump share data and in June’s release.

    Furnaces are still falling

    Gas furnace shipments are down 5.1% year to date at 1,818,744 units, although they remain above the 1,718,336 shipped in the same period of 2024.

    Year to date 2026 2025 Change 2024
    Gas warm air furnaces 1,818,744 1,915,641 -5.1% 1,718,336
    Oil warm air furnaces 17,641 15,490 +13.9% 14,094

    Oil furnaces rose 13.9% year to date, but the whole category is 17,641 units, about 103 times smaller than gas. A large percentage move on a small base is not a trend. The 95% AFUE standard arriving in December 2028 is the change that will matter to furnace volumes.

    Water heaters

    Gas storage water heaters rose 5.2% in July while electric fell 3.9%. Year to date both fuels are down.

    Residential storage water heaters July 2026 July 2025 YTD 2026 YTD change
    Gas 333,499 316,999 2,487,389 -2.5%
    Electric 385,594 401,319 2,877,192 -5.2%

    Electric storage shipments are down 5.5% against 2024 as well, so this is a two-year decline rather than a single soft year. Our water heater replacement guide covers what the federal minimums require.

    What these numbers are, and are not

    AHRI aggregates data from member companies that take part in its statistics programme. The figures are factory shipments, not installations, not sales to homeowners and not a measure of the installed base.

    AHRI states that no data by state or region is available to the public beyond what it publishes, and that it does no market forecasting. Shipments can also run ahead of demand when distributors build inventory, which matters in a year when equipment prices are at a series high.

    Frequently asked questions

    How many heat pumps were shipped in July 2026?

    413,679 air-source heat pumps, up 17.6% from 351,913 in July 2025, per AHRI’s July 2026 statistical release. That is 45.1% of the 916,830 central air conditioners and heat pumps shipped in the month.

    Are heat pumps outselling air conditioners?

    Not yet. Year to date through July 2026, heat pumps were 2,570,228 units against 3,063,290 air conditioners, a 45.6% share. That share was 42.1% over the same period in 2024, so the gap is closing.

    Are HVAC shipments growing in 2026?

    Against 2025, yes: combined air conditioner and heat pump shipments are up 5.5% year to date. Against 2024 they are down 126,433 units, or 2.2%, so 2026 is a recovery from a weak 2025 rather than a new high.

    What happened to furnace shipments?

    Gas warm air furnace shipments are down 5.1% year to date at 1,818,744 units, though still above the 1,718,336 shipped in the same period of 2024. Oil furnaces rose 13.9% from a very small base of 15,490 units.

    Methodology and limitations

    All figures are from the AHRI July 2026 US heating and cooling equipment shipment release, published September 11, 2026. Percentage changes against 2025 are AHRI’s; two-year comparisons and share calculations are ours, from AHRI’s published tables.

    • Shipments are factory data from participating AHRI members, not installations or retail sales.
    • AHRI publishes no state or regional breakdown and does no forecasting.
    • Units under 65,000 Btu/h are residential in AHRI’s tables; 65,000 and above are commercial.

    Sources

    1. Air-Conditioning, Heating, and Refrigeration Institute, July 2026 US heating and cooling equipment shipment data, published September 11, 2026.

    The HVAC Brief is an independent trade publication. We do not sell equipment, take manufacturer advertising, or accept payment for placement in our research. Corrections welcome.