ISSUE GUIDE
A furnace that fails to start can leave your home without heat and may signal mechanical or electrical issues.
Heating failures may involve gas or electrical hazards.
Common causes include ignition failure, sensor problems, or control board issues.
Check thermostat settings and confirm power supply.
Replace thermostat batteries and reset the furnace if safe.
Avoid internal furnace repairs.
If the furnace remains inactive, contact an HVAC technician.