The Denver Homeowner's Fall HVAC Checklist

Denver’s first hard freeze usually lands in mid-October, and the week it happens is the busiest of our year. Do these before then and you’ll skip the line.

Five-minute jobs

1. Check the furnace filter. Hold it up to a light; if you can’t see through it, replace it and write the date on the edge in marker. Then check it monthly. Every home is different, and pets, dust, and smoke season all shorten the interval.
2. Run the heat for ten minutes. Even if it’s warm out. A burning-dust smell for a minute is normal; anything else is not.
3. Test the CO detector. Press the button. If it’s more than seven years old, replace it. Put one on every floor and near bedrooms.
4. Clear the area around the furnace. Three feet of clearance. No paint cans, no cardboard, no cat litter (the ammonia corrodes heat exchangers).
5. Check the outdoor flue and intake pipes. On high-efficiency furnaces those white PVC pipes on the side of the house need to be clear of leaves, nests, and snow.

Fifteen-minute jobs

6. Clear the outdoor AC or heat pump. Pull leaves and cottonwood off the fins and keep a foot of space around it. A heat pump runs all winter, so it needs that space year-round.
7. Reverse the ceiling fans. Clockwise on low pushes warm air down from the ceiling.
8. Seal obvious drafts. A stick of incense near windows and outlets on a windy day shows you where the leaks are.

Call-somebody jobs

9. Book the furnace tune-up. Combustion analysis, heat exchanger inspection, flame sensor cleaning, gas pressure check. This is where we find the cracked heat exchangers and failing inducer motors before they leave you cold. Comfort Plan members get this done automatically.
10. Get the humidifier serviced. Denver’s winter indoor humidity drops below 15% without one. If you have a whole-home humidifier, it needs a new water panel every fall and a check that the solenoid still opens.

The one that saves the emergency call

Number nine. A sizable share of the no-heat calls we run in January are things a tune-up would have caught in October: a flame sensor at the end of its life, a capacitor reading low, a pressure switch hose cracking with age. Twenty minutes in the fall beats a cold night in winter every time.