Why Is My Furnace Making A Clicking Noise?

Why Is My Furnace Making A Clicking Noise?

Your furnace is most likely making a clicking noise due to your furnace’s spark igniter trying to ignite the pilot light/burners. A repeated clicking indicates a failure/system malfunction. This problem is especially troublesome when you are not getting heat at some point during the very cold winter months.

This issue is one we do NOT recommend handling yourself. A specialized HVAC technician is the only one equipped for this issue. If you live in St. George, you can give us a call at Alpine Temperature Control to come to diagnose and treat your clicking furnace.

Keep reading if you are curious about the clicking and would like to understand the problem further. Let’s cover the basics:

  1. What is an ignition system?
  2. Common reasons your furnace clicks?


What Is An Ignition System?

The ignition system in your furnace works like the ignition system in your car. The ignition starts the car or the furnace. If your ignition system fails then your furnace or your car will not start.

Let’s go over the process of your furnace starting. This will give you a better grasp of your furnace’s ignition system.

  • Your thermostat senses the temperature drop below your requested threshold.
  • The fan motor turns on to pull air to the burner.
  • The ignition system gets approximately one minute to energize.
  • The gas valves open.
  • The furnace burners are lit.
  • The blower, after a delay, turns on again to distribute the heated air throughout your home.

The step involving the energizing of the ignition system is where the furnace is failing and causing the “clicking” noise you may be hearing.

The spark igniter repeatedly attempts to light gas and burners — causing the “clicking” noise.


What Are The Common Reasons Your Furnace Clicks?


The thermocouple is a flame sensor that detects flame and opens the valves to release gas. If the flame sensor is malfunctioning then it will not detect the spark igniter so it will not open the valves and let the gas through.

Pilot light/flame issues:

The pilot flame may not be hitting that flame sensor due to an incorrect mixture of gas and air. This can result in the “clicking” noise.

The gas valve isn’t energized: 

If there is no gas, there is no heat. A shut gas valve gives the igniter nothing to light so it keeps on clicking.

All of the above are issues an HVAC technician should fix. You can call us at Alpine Temperature Contol in St. George. We are happy to come out and diagnose that “clicking”!