How To Tell If Furnace Ignitor Is Bad and Needs Replacement

During winter, just the thought of dealing with home heating problems is stressful enough. No one wants to spend a day in a freezing house or office because the furnace won’t work. 

However, sometimes it happens, and you have to figure out where the problem is as soon as possible. Today, we will look at one of the major reasons why your furnace might suddenly stop working – a bad or broken furnace ignitor.

But what exactly is a furnace ignitor? And, what does it do?

It’s essential to understand this first, before learning how to tell if the furnace ignitor is bad or not.

What is a Furnace Ignitor?

Older gas furnaces never had furnace ignitors. Instead, they had a pilot light, which they used to ignite the gas, allowing the furnace to heat the house.

Newer models now use electric furnace ignitors to get the furnace running and heating the place. A furnace ignitor is a small but crucial component in a furnace. It helps to light up the burner, sparking a combustion process that converts gas into heat.

Note:  If the furnace ignitor is broken or faulty, your gas furnace will not ignite. This means that if your furnace fails to start, it’s wise to check whether the furnace ignitor is in good shape.

But how will you know this component isn’t working? Check out the following guide.

How to Check if Furnace Ignitor is Bad

While there are numerous reasons why your furnace might fail to work, the following signs will signify a bad furnace indicator.

  1. The Furnace Won’t Start

If you are trying to increase the temperatures in your home but can’t, this could be because your furnace ignitor is faulty. A broken furnace ignitor might cause your furnace not to come up at all. This causes the temperatures to keep on dropping no matter the settings on your thermostat.

To ascertain that you are dealing with a bad furnace ignitor issue, follow these two steps:

  • Ensure that you have the right setting on your thermostat (heat).
  •  Confirm that the temperatures are set high enough to allow the furnace to provide warm air.

If everything seems right with the thermostat, check the breaker box to ensure that the furnace switch hasn’t tripped. If the switch is on, there is a high chance that your furnace ignitor is broken. However, it could also indicate a more serious electric issue.

This means that you might need to contact a qualified HVAC technician if you aren’t so keen in that area.

  1. Cold Air from the Furnace

Sometimes, the furnace won’t shut down even when the furnace ignitor is broken. However, it will only be blowing cold air into your house.

This is because, with a faulty ignitor, there is no spark to start the combustion process that provides warm air to your house. Therefore, the furnace will only be blowing air with similar temperatures as that of the outside environment.

But, before concluding that your furnace ignitor has an issue, follow the steps mentioned in point one to check your thermostat.

If the thermostat is on “heat” mode but still blowing cold air to your house, it means there are some heating problems. And, the furnace ignitor might just be the culprit.

Without the ignition, there is no combustion, and without the combustion, there is only cold air coming from the furnace.

  1. The Furnace Suddenly Stops Blowing

Most heating systems come with built-in safety measures to help protect you and your home in case a serious problem occurs with the system. For instance, the furnace might suddenly shut off if a furnace ignitor is broken.

So, if the furnace was blowing warm air through the vents, but suddenly cold air started coming out, it could be a sign of a broken furnace ignitor.

However, this might also be caused by a dirty air filter or blocked air ducts. For this reason, follow these steps to confirm your suspicions.

  • Check whether the air filter is dirty. A dirty air filter will hinder the proper flow of air through the furnace and sometimes make the furnace shut down.
  • Check if there is any debris near the air filter, inside the furnace, or in the air ducts. If there is debris, they could be the ones blocking airflow, causing your furnace to stop working.

If the air filter is clean and the air passageways are free from debris, then an ignitor problem might be your most probable suspect.

  1. The Furnace Keeps Turning On and Off

Another reliable indicator of a bad furnace ignitor is a furnace short-cycling. This is when your furnace continually turns on and off.

Generally, this is a safety measure, which occurs when your furnace detects a serious potential safety issue. If you notice such behavior with your furnace, you might want to check if the ignitor is the cause. A faulty ignitor can’t maintain a charge to allow the furnace air to be heated. This forces the system to shut down for around 60 seconds before restarting.

To prevent any further damage to your heating system, you might want to call a qualified HVAC technician to diagnose the problem as soon as possible.

  1.  Furnace Clicking but not Turning On

Sometimes you might hear a clicking sound in your furnace, but the system doesn’t come on. This “click” sound is usually the sound of the furnace ignitor trying to create a spark to heat up the burner.

If the click sound occurs, but nothing else happens with the furnace, it might signify an issue with your furnace ignitor. If you are comfortable inspecting the ignitor yourself, you can go ahead and check whether it’s surely the cause of the problem. If not, seek the services of a local HVAC technician to get the furnace checked and serviced.

Remember not to rush to conclusions as there might be other reasons for these signs. Be sure it’s the furnace ignitor before taking any further steps.

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