thermostat clicks but

5March 2023

thermostat clicks but furnace doesnt start

Have you ever experienced the frustration of turning up the thermostat, and hearing a click, but the furnace doesn’t start?

This is a common problem that homeowners encounter during the winter months.

Fortunately, there are a few simple steps you can take to troubleshoot the issue.

  1. Check the thermostat settings: Make sure the thermostat is set to the “heat” mode and the temperature is set high enough to trigger the furnace to turn on. If you have a programmable thermostat, double-check that the schedule is set correctly.
  2. Replace the batteries: If your thermostat has batteries, replace them with fresh ones to ensure that the thermostat is getting enough power to operate.
  3. Check the furnace switch: Locate the switch that controls the power to your furnace and make sure it is turned on.
  4. Inspect the air filter: A dirty air filter can prevent the furnace from starting. Remove the filter and inspect it for dirt and debris. Replace it with a new one if necessary.
  5. Check the circuit breaker: If the furnace is not receiving power, check the circuit breaker to ensure that it hasn’t tripped.
  6. Inspect the furnace flame sensor: A malfunctioning flame sensor can prevent the furnace from starting. Inspect the sensor and clean it with a soft cloth or fine-grit sandpaper.
  7. Call a professional: If you’ve gone through these troubleshooting steps and the furnace still won’t start, it’s time to call a professional HVAC technician. They can diagnose the issue and perform any necessary repairs.


If your thermostat clicks but your furnace doesn’t start, it can be frustrating and uncomfortable.

However, most of the time, the issue can be resolved with a few simple troubleshooting steps.

Checking the thermostat settings, replacing batteries, inspecting the air filter, and checking the circuit breaker are all easy steps you can take on your own.

However, if these steps don’t solve the problem, it’s important to call a professional HVAC technician to ensure that your furnace is functioning properly and to avoid any potential safety hazards.