Winter Check In: Furnace Igniters

This winter, we’re trying to stay as warm as possible. To do this, we’re taking extra steps to make sure that our home furnaces are operating safely and optimally. The last thing we want is to have to deal with a last minute furnace repair in the dead of winter. Basic furnace and HVAC maintenance and repair is straightforward and easy. 

This week, we’re focusing on furnace igniters - specifically, hot surface igniters. There are four types of igniters for different types of furnaces that one might find. The most common these days, however, is the hot surface igniter. 

The furnace igniter is responsible for heating and igniting the gas connected to the heater. Basically, it provides the heat for the warm air that flows from the furnace. In the past, furnaces used an open flame in the form of a pilot light to heat the gas. These days, hot surface igniters are used instead.

You can find the igniter typically behind the burners of your furnace, across from the flame sensor on the other side. If your igniter is working properly, you will be able to see it glow bright orange when your furnace is in operation. If the igniter is not glowing, then it may be burnt out and not operating properly. 

In the case where the igniter is visibly glowing bright orange but the burners are not igniting, it could be an issue with the gas valve, or with the gas connection to the heater. When your thermostat calls for heat, the inducer motor will turn on and then the gas valve will open. You will be able to hear the gas valve open shortly after the inducer motor kicks on. You should be able to hear the whoosh of the gas flowing through the furnace.

If you see that the furnace igniter is glowing but do not hear the gas valve open, then the problem isn’t the igniter, it’s the gas valve. If you are in this situation, you can contact a technician to examine your gas valve and your furnace to locate the problem. 

Problem: The igniter is not glowing

If the igniter is not glowing while the furnace is running and no heat is being generated, you can check to see if the igniter is operating properly using a multimeter. We do not recommend that anyone without the proper knowledge and experience test their igniter with a multimeter without the assistance of a trained technician. If your igniter is not glowing while the furnace is on, please contact a trusted technician to assist you in testing the igniter.

However, if the igniter is not glowing but has some kind of visible cracking or damage, it is safe to say that it must be replaced. 

If you need to buy a replacement furnace igniter, we offer many options at Snap Supply. Make sure to take a look at cross reference information and model numbers to confirm that the part you are looking at is right for your furnace.