Last reviewed: September 2026 · By the HVAC Brief Editorial Team · Our sourcing and editorial standards
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.
- 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.
- Temperature rise or temperature split. The difference between return and supply air, compared with the range on the equipment data plate.
- 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.
- Motor amp draw. Compared with the nameplate rating, it shows a motor beginning to fail.
- Combustion readings on the heating side. On any gas or oil appliance, plus a check for spillage at the draft hood.
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
- ENERGY STAR, Maintenance Checklist.
- 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.
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