The short answer
Your heater sat idle for eight months. Test it in October, not on the first freezing night. The February 2021 freeze showed what happens when Texas heat fails at scale: pipes burst and homes went cold for days. A fall check is cheap insurance against joining the repair rush when the first cold snap arrives.
Fall checklist: do these yourself
- Replace the air filter. A clogged filter starves the system of airflow, which overheats furnaces and freezes up heat pumps.
- Run the heat for 20 to 30 minutes in October. Do it on a mild day before you need it. Listen for new noises and check that warm air comes from every vent.
- Test the thermostat. Switch to heat mode and set it five degrees above room temperature. If the system does not respond, you found the problem early.
- Clear vents and returns. Move furniture and rugs off supply vents and keep return grilles unblocked.
- Check carbon monoxide detectors. Press the test button, put in fresh batteries, and make sure there is one on every floor. This is the single most important safety item for a gas furnace.
- Clear the outdoor unit (heat pumps). Pull leaves and debris away from the outdoor unit and keep two feet of clearance around it.
What a professional tune-up covers
A fall tune-up runs $80 to $170 for a gas furnace in the Dallas area, and it covers what you cannot check yourself:
- Heat exchanger inspection. The safety-critical check. Cracks in the heat exchanger can leak carbon monoxide into your home.
- Burner cleaning and inspection. Dirty burners waste gas and soot up the system.
- Ignitor and flame sensor. The two parts most likely to cause a no-heat call on the first cold night.
- Gas pressure and combustion check. Confirms the furnace is burning cleanly and venting properly.
- Blower and airflow. Weak airflow means cold rooms and a strained system.
Book in fall, not December. Off-season demand often means better pricing, and scheduling is easiest before heating season.
Heat pumps in Texas winters
Heat pumps handle most of a DFW winter efficiently, which is why they are common here. Two things to know: output drops as temperatures fall into the 30s, when auxiliary heat strips take over and your electric bill climbs. And the outdoor unit needs clear airflow, so keep it free of leaves, mulch, and ice buildup. If your heat pump runs constantly on mild days without keeping up, that is a service call, not normal operation.
Call a tech now if you see these
- A carbon monoxide detector alarms. Leave the house and call the fire department, then your HVAC tech. Do not go back inside to investigate.
- You smell gas. Leave the house and call your gas utility or the fire department from outside.
- The burner flame is yellow instead of blue (gas furnace). Yellow or flickering flame can signal incomplete combustion. Call a tech.
- No heat after the basic checks. If the filter is clean, the thermostat is set right, and breakers are on, but there is still no heat, stop troubleshooting and call a licensed tech.
Common questions
When should I test my heater in Texas?
October. Run the heat for 20 to 30 minutes on a mild fall day, before you actually need it. That gives you weeks to schedule a repair instead of joining the rush when the first cold snap hits.
Do I need a heater tune-up every year?
Annual fall tune-ups are the standard recommendation, and there is a paperwork reason too: manufacturers can deny warranty claims if you skipped maintenance. A tune-up runs $80 to $170 for a gas furnace in the Dallas area, which is cheap compared to a no-heat emergency call.
Will my heat pump keep up in a hard freeze?
Through a normal DFW winter, yes. Heat pump output drops as temperatures fall into the 30s, when auxiliary heat strips take over and heating bills rise. In single-digit extremes like February 2021, every system type strains, so have a backup plan for the coldest nights.
How do I know my gas furnace is safe?
Three checks: working carbon monoxide detectors on every floor, an annual professional inspection of the heat exchanger (cracks can leak carbon monoxide), and a steady blue burner flame. A yellow or flickering flame means call a tech.
Sources
- Porch, "Top 10 Furnace Repair Services in Dallas, TX 2026": porch.com: gas furnace tune-ups $80 to $170 in Dallas; neglected annual maintenance can void the manufacturer warranty.
- Jupitair HVAC, "Furnace Repair Cost: $150-$2,500 in North Texas (2026)": jupitairhvac.com: common North Texas repairs from recent invoices include flame sensor work at $150 to $200 and ignitor replacement at $200 to $400.
Safety guidance reflects standard HVAC industry practice. If you suspect a gas leak or carbon monoxide, leave the house and call emergency services first.