There are many reasons for furnace failures. Listed below are the 10 most common, all under $200…

  1. Dirty filter
  2. Dirty evaporator coil
  3. Bad high limit switch from dirty filter or evaporator coil
  4. Bird or mouse stuck in draft inducer fan motor
  5. Dirty or bad flame sensor
  6. Bad hot surface igniter
  7. Bad thermocouple
  8. Bad pressure switch
  9. Loose mulex plug
  10. Bad thermostat