Annual AC maintenance: what actually matters and what's upsell
The 14 items that genuinely belong on a tune-up checklist, and the 5 that are usually upsell.
What genuinely belongs on a real tune-up
Refrigerant pressures (high and low side gauges). Without these readings, the tech literally can't tell if the system is operating correctly.
Capacitor microfarads check. Capacitors degrade gradually before failing. A measurement below nameplate by 6%+ means replace before next summer.
Condenser coil cleaning. Most-impactful single thing on efficiency. Should be a real coil cleaner spray + rinse, not just a once-over with a blower.
Filter inspection and (if homeowner provides) replacement.
Drain line clear and condensate pump test. Clogged drains cause water leaks inside the home — preventable.
Blower motor amp draw and bearing check.
Electrical connections check (tightness, signs of arcing).
Contactor visual inspection (pitting indicates near-end-of-life).
Refrigerant line insulation inspection.
Thermostat calibration check.
Temperature differential supply vs. return (should be 18-22°F on a properly functioning system).
Full operational check including a low-voltage shutdown to confirm safety circuits work.
What's usually upsell
Surge protectors at the disconnect. Sometimes worth it, sometimes pure markup. Get a quote and compare.
UV light for the evaporator coil. Limited evidence of efficacy beyond visible mold control. Skip unless your system has documented mold issues.
Whole-house humidifiers in dry climates without occupant complaints. Often unnecessary.
'Lifetime' condenser warranty extensions. Read the fine print — usually parts only, not labor, and excludes refrigerant. Almost never worth it.
Refrigerant 'top-offs' on a system that doesn't have a leak. If your refrigerant is low, you have a leak. Adding refrigerant without finding the leak is a band-aid that violates EPA regulations on refrigerant handling for systems above 5 lb.
How often to do maintenance
Annual minimum. Spring tune-up before peak cooling season is the most-impactful single visit.
Twice-yearly (spring AC, fall heating) on premium maintenance plans. Worth the upgrade in mixed-fuel homes (gas heat + AC).
Quarterly: filter changes (or monthly if you have pets/allergies).
If you skipped maintenance: don't worry, just do one this year. The system will be okay; you'll just have a slightly higher utility bill until the next tune-up.