Seasonal Checklists

Winter HVAC Checklist

Quick answer

Winter HVAC care centers on keeping heat reliable through the coldest stretches: monthly filter checks under heavy runtime, keeping furnace intake and exhaust vents clear of snow, letting heat pumps defrost without panic, protecting pipes during outages, and treating any heat loss below freezing as an emergency worth same day service.

Mid winter habits

Heating runs hardest exactly when failure is most dangerous. These habits maintain margin.

Check filters monthly; winter runtime clogs them as fast as summer
After every snowfall, clear furnace intake and exhaust pipes at the exterior wall, the top cause of mystery furnace shutdowns in snow country
Keep heat pump outdoor units clear of drifted snow with a foot of open space, and never let roof slides bury them
Maintain CO detector discipline during the months of maximum combustion
Hold thermostat setbacks modest, 2 to 4 degrees, on heat pumps to avoid auxiliary heat penalties

Cold snap and outage protocol

During extreme cold, systems run continuously and struggle to hold setpoint, which is design behavior. Help them: drop expectations a degree or two, close blinds at night and open sun facing ones by day, and resist cranking heat pumps far above setpoint, which simply engages resistance heat at triple cost.

If heat fails below freezing: check breakers, switch, filter, and thermostat first, then call immediately and say the words no heat, which triages you ahead of maintenance calls at every reputable company. While waiting, open cabinet doors under sinks on exterior walls, let faucets drip, and close off unused rooms. Pipes freeze in walls within hours near 20 degrees; below that, consider moving vulnerable occupants somewhere warm.

Heat pump winter behavior is not failure

Winter heat pump service calls are dominated by normal behavior reported as failure. Steam billowing off the outdoor unit is defrost. The whoosh and momentary cool air indoors during defrost is normal. Frost on the coil that clears within an hour is normal. Long continuous running in cold weather is efficient design, not distress. Call for service when ice encases the unit and never clears, when auxiliary or emergency heat runs constantly in mild weather, or when indoor temperature actually falls while the system runs.

Frequently asked questions

Why did my furnace stop working during a snowstorm?

The most common storm failure is the simplest: snow blocking the intake or exhaust pipes on the exterior wall, which trips a pressure switch and locks the furnace out. Clear the pipes, cycle power at the furnace switch, and most units restart. Recurring trips after clearing warrant service.

What temperature should I keep my house in winter?

68 degrees while home and awake is the standard efficiency baseline, with modest setbacks while away or sleeping. Never set below 55 in a plumbed home, and heat pump owners should keep setbacks to a few degrees so recovery does not trigger expensive auxiliary heat.

Is it bad for a furnace to run constantly in extreme cold?

No. At or below design temperature, roughly the coldest 1 percent of hours, continuous running is exactly what sizing intends, and modulating furnaces are happiest doing it. Losing indoor temperature while running constantly, however, means lost capacity worth investigating.