Season by season4 min readOctober 1, 2026
How to get your heating ready for a North Texas freeze
Run your heat for ten minutes on a mild day in October, replace the filter, clear the area around the furnace and outdoor unit, and book a heating tune-up before the first freeze. Most first-cold-morning failures are a dirty flame sensor or a filter that was never changed.
Test it before you need it
The first cold morning of the year is when every furnace that was ignored all summer fails at once, and it is when every HVAC company in Collin County is booked solid. Testing in October costs nothing and moves you out of that line.
- Set the thermostat to Heat, three degrees above room temperature, and let it run ten minutes
- Listen for repeated clicking without ignition, or a start followed by a shutdown within seconds
- Check that every register is warm. A cold room usually means a duct problem, not a furnace problem
- A burning-dust smell for the first few minutes is normal. A smell that persists, or any gas smell, is not
What to do yourself
Replace the filter. A restricted filter is the single most common cause of a furnace overheating and shutting down on its limit switch. Clear stored boxes away from the furnace and make sure the outdoor heat pump, if you have one, is not buried in leaves. Test the carbon monoxide alarm, and buy one if the house has gas heat and no alarm.
What a tune-up covers
A heating tune-up checks combustion, cleans the flame sensor, tests the ignition sequence, inspects the heat exchanger, confirms the safety controls work and measures carbon monoxide at the supply. On heat pumps it tests the defrost cycle and the backup heat strips. Do it in October, before the first norther, while the calendar is open.
During the freeze itself
Keep the thermostat steady rather than turning it down at night; a heat pump asked to recover five degrees on a 15-degree morning runs on the expensive strips for hours. Open cabinet doors on exterior-wall plumbing and let faucets drip, because frozen pipes do far more damage than a cold night. If the power goes out, a gas furnace still needs electricity for the blower and controls, so plan for that like 2021 taught everyone to.
Questions on this
My heat pump is steaming outside in the cold. Is it broken?
Almost never. A heat pump in defrost mode melts frost off the outdoor coil and the steam is the result. It lasts a few minutes and the house may get a brief puff of cool air. Steam that lasts far longer, or a coil that stays caked in ice, is a call.
Why does the furnace smell like burning the first time it runs?
Dust that settled on the heat exchanger and burners over the summer burns off in the first ten minutes. If the smell is electrical or lasts past the first cycle, turn it off and call.