Why Won’t My Furnace Turn On?
A furnace that does not start may have a thermostat, power, ignition, condensate, or safety-control issue. Check the safe basics, note any indicator code, and avoid repeated resets.
Read the guide →Homeowner checks
Change or clean filters as the manual directs, keep vents and returns clear, and keep the area around the furnace clean and unobstructed.
Technician checks
Ignition and flame sensor, burners and combustion, blower and motor, heat exchanger, safeties, thermostat calibration, and venting. These checks need tools and training — do not open sealed or gas components yourself.
Timing
Book maintenance before the heating season, so faults are found in autumn, not on the coldest night of winter.
Key takeaways
- Keep filters clean and vents clear, as the manual directs.
- Book a technician check before the heating season, not during the first cold snap.
- Never open sealed or gas components yourself — those checks need tools and training.
