4 Signs Of A Failed Gas Furnace Igniter

15 June 2023
Categories: , Blog

Gas furnaces depend upon an ignition system to ignite the fuel that will create the heat. Igniters can fail, though, which means you will need to have the ignition replaced if you want to heat your home.

1. Poor Heating

Poor heating can be a result of a variety of issues, but it is still one of the first symptoms of an ignition problem. When the ignition fails, the furnace may still run but there will be no hot air so only cold air will come from the vents. Verify that the thermostat is set to the desired temperature and on the "furnace" setting. If it is and poor heating is still a problem, then it's time to have the ignition inspected to see if it is the problem.

2. Frequent Cycling

A cycling furnace is one that is coming on and then turning off a few minutes later, just to come back on again and repeat the entire process. Not only is it annoying, but a cycling furnace will also suffer from greater wear and tear while heating the house poorly. Cycling can be caused by ignition failure. The furnace attempts to come on, but the igniter doesn't ignite the fuel so the furnace cycles down a few minutes later. Frequent cycling due to ignition problems usually happens in conjunction with poor heating.

3. Abrupt Shutdowns

Most furnaces have safety switches that shut down the system in the event of ignition and fuel combustion issues. Unlike cycling, your furnace will power on and then immediately go into shutdown mode without trying to cycle back on again. The reason for the shutdown is because the fuel isn't igniting and burning off at all, so the safety sensor shuts down the furnace so that the fuel won't be leaking into your home without igniting.

4. No Flame

Sometimes it's easy to see if there is an ignition problem. You can open the door to the combustion chamber and check for the pilot light, which should be a small unwavering blue flame. If there is no flame when the furnace clicks on, or if the flame is inconsistent or any color but blue, there is an issue in the ignition system or fuel valve. Some furnaces have a flameless ignition system, which uses a heated element to ignite the fuel. You should be able to see the glow from the element at the time of ignition if it is working properly.

Contact a furnace repair service if you suspect there are issues affecting your ignition system.

About Me

I almost always have my air conditioner inspected every spring before I start using it in the summer. However, last year I decided to skip the inspection. Everything had been OK for the last couple of years, so I assumed that it would be fine this year as well. Why not save a few dollars and skip the annual check up, just this once? Of course, this was the year that my air conditioner decided to break down. It ran for a few days, but it never really seemed to get cool enough to bring the indoor temperature down. Then it started making a loud noise, right before shutting off completely. By that time, the AC repair company was swamped like it always is when the weather is warm, and I had to wait days for an appointment. Next year, I will definitely be getting that yearly inspection first.