Why won’t my furnace turn on?

There are several factors that play into diagnosing this furnace problem, such as the age of your unit and whether it has been regularly maintained. It’s difficult to find the solution without a proper diagnosis. However, here are the most common reasons a furnace fails to turn on.

  • Faulty thermostat – Verify the thermostat is switched to “heat”, the temperature is set correctly and the fan is set to “auto”. If you are still experiencing problems, you may need to replace the batteries or get a new thermostat.
  • Tripped or blown circuit – Your furnace is likely on its own circuit, so if it is tripped or blown, you may not notice until you try to turn your furnace on. Check your circuit breaker.
  • Malfunctioning pilot light – A pilot light can go out for a number of reasons. If you are unsure of why your pilot light has gone out, please contact a professional that can help diagnose and repair the problem.


Horsch & Miller Plumbing and Heating

136 Kettle Moraine Drive North
Slinger, WI 53086