The Warning Signs of a Faulty Furnace Ignitor

The Warning Signs of a Faulty Furnace Ignitor

The Warning Signs of a Faulty Furnace Ignitor

When winter temperatures are here, you don't want to deal with issues heating your home. Waking up to a cold house or spending the day in a frigid office with a broken furnace can ruin your day.

It can seem like your furnace goes out when you need it most. Even with preventive maintenance, your furnace can misbehave on the coldest days of the year. Sometimes it's a quick fix. In other cases, you could have a faulty furnace ignitor.

What is the furnace ignitor? How do you know if it's the problem? Keep reading for everything you need to know about your furnace ignitor and what to do if the warning signs point to a problem.

What Is the Furnace Ignitor?

Older furnaces used a pilot light to heat the air blowing into your home. Every year before the temperatures dropped, you probably noticed your parents bravely light the pilot light in the furnace.

Today, the furnace igniter replaces the open flame of the pilot light in most furnaces. Without the ignitor, your heater won't blow hot air. It's a critical part of your furnace system, and one of the most common reasons your furnace doesn't work correctly.

You've probably heard the "click" from your furnace before the air starts blowing. When the thermostat kicks on to start the furnace, the ignitor creates a spark that "ignites" the gas connected to your heater. Other types of ignitors heat without a spark. Instead, these ignitors heat up and touch the surface of the gas to heat the air blowing from the furnace.

No matter which type of ignitor is in your furnace, this chain of events lights your heater so that it blows hot air.

Don't worry—an ignitor that goes bad is common for most furnaces. Fortunately, you can replace the ignitor without replacing the full furnace. Most ignitors last about seven years. Keep reading to learn how you can tell if your furnace problem is a faulty ignitor.

How Do I Know if There's a Problem?

A furnace that doesn't work could have a variety of issues. Some of the most common symptoms could the cause of several different problems. Here are a few indications that you have a faulty ignitor.

No Cold Air

If you have a faulty furnace ignitor, it won't produce that small spark to heat the air coming from your furnace. Without it, your heater blows air at the same temperature as the cold outside air.

Cold air blowing through your vents is a good sign that you have a heating problem within the furnace. However, there could be a more straightforward fix.

  • Check the thermostat to make sure the setting is "heat" instead of "cool."
  • Make sure the temperature is set high enough to tell the furnace to blow hot air.

If the thermostat's setting is okay, the next simplest solution could be a problem with the ignitor.

The Furnace Won't Come On

If you notice your home getting colder and colder, yet the furnace never comes on, no matter how high you set the temperature, this could indicate a problem with the ignitor.

Perform the thermostat checks mentioned above. Next, check your breaker box and make sure the switch connected to your furnace hasn't tripped to "off." Here's how to find it if you've never needed to locate your breaker box.

Take a look at the switch that controls the power to your furnace. If the furnace breaker is "on," there could be an issue with the ignitor, or you could have a more significant electrical issue.

The Furnace Suddenly Stops Blowing

Your furnace has built-in fail-safes to keep you and your house safe when there is a problem with the system. If you enjoy the warm air from your furnace, but it suddenly stops blowing, that could indicate a sudden problem with the ignitor.

  • Check the air filter. If it's dirty, air can't flow properly through the furnace. This could cause your furnace to stop blowing.
  • Check for debris where the air filter sits inside the furnace and in your air ducts. Anything blocking the flow of air through the filter or your vents can cause the furnace to shut off.

If the air passageways seem free and clear and you have a clean air filter, your next best option is to check the ignitor for a problem.

Starts, Then Stops, Then Starts Again

If your furnace goes on and off frequently, the ignitor could be the culprit. An ignitor that's on its way out can't hold a charge long enough to heat the furnace air. Plus, your furnace probably has a safety feature that forces your system to wait at least 60 seconds before it starts again.

Repeatedly going on and off is bad your furnace. To save yourself from a more significant furnace issue, look for the problem as soon as you notice it cycling on and off a few times.

Tripping the Breaker More Than Once

We mentioned checking the furnace breaker to make sure it's on. However, if your furnace keeps tripping the breaker soon after it starts blowing air, the culprit could be a faulty ignitor.

Repeatedly tripping the breaker is bad for your furnace and your home's electrical system. While the ignitor can be a simple fix, don't let the furnace continue to trip the breaker more than a few times. Leave the breaker set to "off" while you repair the furnace problem.

I Hear the Click, But Nothing Happens

That "click" we mentioned earlier is the sound of your ignitor trying to warm the fuel in your furnace. However, if you hear the click but the air doesn't blow soon after, you could have a dangerous ignitor problem.

Before you get further inside your furnace system to check the condition of the ignitor, be sure you know what to look for and how to get to it!

How Do I Check the Ignitor?

If you're comfortable getting up close and personal with your furnace, the ignitor can be a simple thing to find and repair.

Before opening any panels on your furnace:

  1. Make sure to unplug the furnace from the wall. You don't want any power to the furnace while you attempt to find the ignitor and replace it.
  2. Turn off the gas valve. Make sure no gas flows into the furnace while you work on it.
  3. Make sure the furnace is room temperature before opening any panels. A hot furnace can burn you if you touch it.

Getting to the working components of your furnace can be dangerous! Make sure it's safe before going further.

What Does it Look Like?

You'll need to know what the ignitor looks like to make sure you don't mess with the wrong parts inside your furnace. After removing the burner panel door from the furnace, look for a small device connected between the electrical wires and the furnace near the gas input.

  • A typical surface ignitor has a white ceramic base with a flat metal surface coming from it.
  • A spark ignitor often has two metal prongs that generate the spark.

After you've located the ignitor, see if you can identify a problem with it.

What Are the Possible Ignitor Problems?

A faulty ignitor can cause any one of several problems:

  • Old and worn out. If the ignitor is several years old, it might simply be at the end of its usable life. It could be time to replace it.
  • The wrong one. Your furnace needs the right kind of ignitor to work. You could get by with the wrong one for a while, but if the last replacement was the wrong ignitor, you need to replace it with the correct one.
  • Bad limiter switch. This switch shuts off your furnace if the temperature gets too hot. If it's faulty, the switch misreads the temperature and shuts off prematurely.
  • Overpowered. If the breaker box blows when the furnace comes on, your ignitor can't handle a power surge.

Without the tools and knowledge to test your ignitor, it can be challenging to identify the problem. However, if you see visible damage, that's a good sign of a faulty ignitor. If it's chipped, melted, warped, cracked, or you see exposed wires, it's time to replace the ignitor.

Check the manual that comes with your furnace. Make sure you have the right ignitor in place. If you need to replace the ignitor, make sure you buy the correct one.

Better yet, call a professional! Don't risk further damage to your furnace or your safety by attempting a repair on your own.

Don't Ignore the Warning Signs of a Faulty Furnace Ignitor

At the first signs of a faulty furnace ignitor, take action. Investigate the symptoms on your own, then call a professional to handle a repair. An ignitor repair or replacement is often an inexpensive fix that can save you from more significant (and expensive) furnace repairs. A professional repair can also protect you from injury or accident.

Don't suffer without furnace heat! Contact us to schedule your furnace check, maintenance, or repair.

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