Routine maintenance is the difference between an HVAC system that lasts 10 years and one that lasts 20. Manufacturers like Trane, Lennox, and Carrier require annual professional service to keep warranties valid. But many “tune-ups” are nothing more than a quick filter swap and an upsell pitch.
Here’s what a thorough HVAC tune-up actually includes, and what to demand from any contractor you hire.
Cooling System (Spring Visit)
- Check refrigerant levels and pressures (high & low side)
- Inspect for refrigerant leaks (electronic leak detector)
- Clean condenser coil — remove debris, leaves, dirt
- Clean evaporator coil if accessible
- Test capacitor microfarad reading
- Inspect contactor for pitting or burning
- Check fan motor amperage draw
- Verify proper airflow at supply registers
- Test thermostat calibration
- Check temperature split (should be 18–22°F)
- Inspect condensate drain pan and clear drain line
- Tighten electrical connections (loose connections cause 20% of failures)
- Lubricate motor bearings if applicable
- Inspect refrigerant line insulation
Heating System (Fall Visit)
- Inspect heat exchanger for cracks (carbon monoxide hazard)
- Test gas pressure and combustion analysis
- Clean burners and flame sensor
- Check ignitor (silicon carbide hot surface) for cracks
- Inspect inducer motor and pressure switch
- Test high-limit and rollout safety switches
- Check belt tension on older models
- Lubricate blower motor bearings
- Verify proper venting and combustion air supply
- Test carbon monoxide levels in flue gas
- Check thermostat anticipator setting
- Replace filter (1″ pleated every 90 days, 4–5″ media every 6–12 months)
Year-Round Items
- Inspect ductwork for leaks at all visible joints
- Check humidifier pad and drain (vital in Colorado’s dry winter)
- Verify smart thermostat firmware updated
- Document equipment model/serial numbers and refrigerant amounts
- Provide written report with photos of any concerns
What to Watch Out For
If a contractor:
- Spends less than 45 minutes per visit — they’re not doing the work
- Doesn’t put on covers/shoe protection — they don’t respect your home
- Won’t show you their gauges or test results — you’re being sold, not serviced
- Tries to upsell a “chemical wash” without explaining why — get a second opinion
The Cost vs. Risk Math
A two-visit annual maintenance plan covers two seasonal tune-ups for a fraction of what a single emergency repair costs. Major component replacements (compressor, blower motor, heat exchanger) can be many times more expensive. Maintenance pays for itself the first time it catches one issue.