Quick answer. A real tune-up measures real numbers — static pressure, airflow, temperature split, electrical readings, and a visual/camera inspection of the parts you can't see — not just a filter swap and a glance.
Checked on every tune-up (furnace and AC)
General system checks
- Static pressure — measures how hard the system is working to push air through the ducts. Too high, and something’s restricting airflow.
- Airflow (CFM) — the actual volume of air the system is moving, not just a guess based on how it sounds.
- Camera inspection inside the system — a borescope look at parts you can't see from the outside, including buildup on the secondary heat exchanger.
- Filter — direction and cleanliness — checked and corrected if it's backwards or overdue.
- Temperature split — the difference between the air going into the system and the air coming out, which tells you whether it's actually heating or cooling to spec.
- Capacitors — tested against their rated microfarads (µF), not just "does it start."
Furnace-specific checks
Heating side
- CO (carbon monoxide) ppm — measured at the furnace to confirm it's burning clean and safe.
- Secondary heat exchanger dirt buildup — found via the camera inspection above; buildup here hurts efficiency and can affect safety.
- Blower motor shaft play — checked for wear that predicts a failure before it happens.
- Exhaust fan amps (on 90%+ high-efficiency furnaces) — the draft inducer motor's amp draw, to catch a motor on its way out.
- Dirt buildup generally through the burner and blower compartment.
Outdoor unit / AC-specific checks
Cooling side
- Outdoor compressor amps — measured against the nameplate rating.
- Outdoor fan amps — same idea, for the condenser fan motor.
- Outdoor capacitor — tested, not just eyeballed.
- Outdoor unit cleanliness — the coil fins need to be clear of dirt and debris to reject heat properly.
Worth noting: indoor blower motor amps aren't part of this standard checklist — the checks above are what actually predict failures and catch problems early.
Why this matters
Most of what determines whether a tune-up actually extends the life of your system, or is just a quick filter change with a invoice attached, comes down to whether these numbers get measured at all. A capacitor that "looks fine" can still be reading well under its rating. A secondary heat exchanger caked with dirt won't show up unless someone actually looks with a camera. Ask what was measured, and ask to see the numbers — a tech who's actually doing the work will have them.
See real numbers on your next visit
Every Canyon Comfort tune-up comes with a System Health Report — the actual readings, not just “looks good.”