HVAC inspection checklist
This is different from a tune-up. A tune-up is a technician doing certified work on the equipment; this is a five-minute walk-around anyone can do, plus what a real estate inspector is actually looking for.
Three different things people mean by "inspection"
The phrase gets used for three separate situations, and mixing them up leads to the wrong expectations. A homeowner's own walk-around is quick, visual, and free. A professional tune-up involves opening panels, taking measurements, and testing combustion or refrigerant systems with certified tools.
A real estate inspection is a third thing again: a generalist inspector checking that the system runs and looks reasonably maintained, not a specialist diagnosing it. This article covers the first and third. For the second, see the tune-up checklist linked below.
| Your own walk-around | Real estate inspection | |
|---|---|---|
| Who does it | You | A licensed home inspector, generalist |
| What it checks | Filter, clearance, obvious damage, thermostat response | Age, visible condition, that it turns on and produces air at the expected temperature |
| What it can't catch | Refrigerant charge, cracked heat exchanger, electrical faults | The same, plus anything not visible or running that day |
What you can actually check yourself
Start with the filter. Pull it and hold it up to a light. If you can't see light through it, replace it, however many weeks it has been in there. Next, walk outside to the condenser or heat pump unit. Confirm it has clear airflow on all sides, with nothing stacked against it and no vegetation growing into the fins.
Back inside, check that supply registers and return grilles are open and not blocked by furniture or rugs. Look at the outside of the furnace or air handler cabinet for rust streaks, especially near the bottom. They often point to a condensate drain problem rather than the cabinet itself failing.
Finally, run the thermostat through a mode change and confirm the system responds within a few minutes. A long delay or no response at all is worth noting, even if it eventually kicks in.
What you cannot check, and shouldn't try to
Refrigerant charge and pressures require gauges and, legally, EPA Section 608 certification to even connect them to the system. A cracked heat exchanger is usually invisible without a camera threaded into the cabinet.
Electrical testing inside the unit, including anything involving the capacitor, carries a shock risk that isn't worth the money saved by skipping a technician. None of these belong on a homeowner's list, and no checklist you find online should be telling you otherwise.
If the inspection is tied to buying a house
A real estate inspector will typically note the age of the equipment (often from a data plate inside the cabinet). And whether it turns on and produces air within a reasonable temperature range. They will also note any visible rust, damage, or obviously deferred maintenance. In most cases they will not verify refrigerant charge, run a combustion analysis, or confirm the heat exchanger is intact.
A system that is 12 to 15 years old and passes a generalist's inspection can still need a compressor or heat exchanger replacement within a year or two. If the equipment is near the end of a typical service life, a separate HVAC-specific inspection before closing is a reasonable thing to ask for, not an overreaction.
How often to run your own checklist
Checking the filter monthly and doing the rest of the walk-around at the start of each cooling and heating season covers most of what a homeowner can catch early. This is the same seasonal rhythm as a professional tune-up, just without the tools. Between the two, most of the failures covered elsewhere on this site get caught before they turn into a no-heat or no-cool emergency.
Frequently asked questions
Is a homeowner walk-around a substitute for a professional tune-up?
No. It catches obvious, visible problems, but it can't test refrigerant charge, combustion safety, or the heat exchanger, which is what most of the risk in an aging system actually involves.
What does a real estate inspector actually verify on the HVAC system?
Generally the age of the equipment, whether it turns on and produces air at a reasonable temperature, and visible condition. A generalist inspector is not doing the same job as an HVAC technician, and their report shouldn't be read as one.
Sources
What this page explains is based on these official sources. If you check one and it does not match what you read here, send it to us and the article gets corrected.
- US EPA. Section 608 Technician Certification
- US EPA. Section 608 of the Clean Air Act