Get your heating ready in October, before the first cold night: change the filter, set the thermostat up correctly for a heat pump (system type, aux lockout, small setbacks) or check the furnace settings, run heat for 20 minutes to burn off dust and confirm warm air, check the outdoor unit and clearances, test smoke and carbon monoxide detectors, and book the fall tune-up. For heat pump homes, the thermostat step is the one that decides whether January’s bill is normal or double.
The checklist
- Filter. Replace. Filter guide.
- Thermostat (heat pump). Confirm system type is heat pump; set an aux lockout (around 35–40°F to start); use setbacks of about 2°F or heat-pump-aware recovery; fan on Auto; emergency heat off. Thermostat settings.
- Thermostat (furnace). Mode to Heat; check schedule; batteries.
- Test run. Heat for 20 minutes. Heat pump: warm (not hot) air, outdoor unit running, no constant “aux” indicator once up to temperature. Furnace: ignition within seconds, steady flame, warm air, no unusual smells beyond initial dust.
- Outdoor unit (heat pump). Clear debris; make sure the unit sits level with drainage beneath it, since defrost water needs somewhere to go and can freeze into a block on a bad pad.
- Furnace safety. Vent/flue clear and connected; nothing stored against the furnace; combustion air not blocked; CO detector on each level with fresh batteries.
- Vents, returns, ducts. Open and unblocked; a quick look at crawlspace and attic ducts for disconnects.
- Book the tune-up. Heat pumps benefit from a heating-season check of defrost and strips; furnaces need the burner, heat exchanger and safety checks. What it should include.
If aux heat runs constantly
That’s the winter problem to catch early: aux heat stuck on. Every contractor on the North Carolina registry shows the license status we found.