Colorado’s climate is tough on HVAC systems. We go from 95°F summers to below-zero winters, often with wild temperature swings in between (hello, 70°F in February followed by a blizzard). Regular maintenance is the single best thing you can do to avoid emergency breakdowns, extend your system’s life, and keep energy bills under control.

Spring checklist (March–May) — get ready for cooling season

DIY tasks:

  • Replace your air filter (do this every 30–90 days year-round)
  • Clear debris from around your outdoor AC unit — remove leaves, grass clippings, and anything within 2 feet
  • Gently rinse the outdoor unit’s fins with a garden hose (don’t use a pressure washer)
  • Check that all vents and registers inside are open and unblocked by furniture
  • Test your AC: turn it on and let it run for 15 minutes. Does cool air come from the vents?
  • Check your thermostat batteries if it’s battery-powered

Professional tune-up should include:

  • Refrigerant level check and leak inspection
  • Electrical connection tightening and voltage testing
  • Capacitor testing (the #1 summer failure point)
  • Evaporator and condenser coil cleaning
  • Drain line clearing (prevents water damage)
  • Thermostat calibration check
  • Overall system efficiency measurement
When to schedule: Book your spring tune-up in March or early April — before the rush. By June, most HVAC companies are booked out 1–2 weeks for tune-ups because everyone waits until the first hot day.

Summer checklist (June–August) — keep it running

  • Change the air filter monthly during heavy-use months
  • Keep the outdoor unit clear of cottonwood fluff (a huge problem along the Front Range)
  • Don’t set your thermostat more than 20°F below the outdoor temperature — the system can’t keep up and will run nonstop
  • Close blinds on south- and west-facing windows during afternoon heat
  • Check for water around the indoor unit (could indicate a clogged drain)

Fall checklist (September–November) — get ready for heating season

DIY tasks:

  • Replace the air filter
  • Test your furnace: turn the heat on and let it run for 10 minutes. A slight burning smell on the first start is normal (dust burning off the heat exchanger). If it persists past 30 minutes, call a pro.
  • Check carbon monoxide detectors — replace batteries and test the alarm
  • Clear anything stored near the furnace (within 3 feet is the safety minimum)
  • Check that the furnace exhaust vent outside is clear of nests, leaves, or snow

Professional tune-up should include:

  • Heat exchanger inspection for cracks (critical safety check)
  • Burner cleaning and flame inspection
  • High-altitude combustion adjustment verification
  • Gas pressure testing
  • Blower motor and belt inspection
  • Safety control testing
  • Carbon monoxide testing at supply registers

Winter checklist (December–February) — keep it running safely

  • Change the air filter every 30–60 days (furnaces run constantly in Colorado winters)
  • Keep the furnace exhaust pipe clear of snow and ice after storms
  • Don’t close more than 20% of registers to “save energy” — this builds pressure and strains the blower motor
  • If you hear banging or popping from ductwork, it’s usually thermal expansion and is normal. Persistent rattling or grinding is not.
  • Know where your emergency shutoff is (gas valve near the furnace) in case you smell gas

How much does professional maintenance cost?

A single professional tune-up typically costs $89–$150 per system. Our Comfort Club membership ($179/year) includes two tune-ups (spring AC + fall furnace), priority scheduling, 15% off repairs, and no emergency service fees. For most homeowners, the membership pays for itself with just the tune-ups.