The Short Answer Is: Warning signs of a bad furnace ignitor include the furnace not starting or
The most obvious sign that your furnace ignitor is bad is that it won't ignite, and this generally manifests itself in your furnace failing to run when you activate it.
You can reset the ignition on your furnace simply. To do this you must cut the power to the furnace first by turning off the circuit that powers it. Once the power is off you can remove the burner door to reveal the ignitor. Turn this to “off” and leave it off for at least 5 minutes.
1. The Furnace Won't Run. When a furnace doesn't run at all, that could be a sign you have a bad ignitor that needs replacing.
Defective Igniter or Pilot Light
If it clicks but your furnace won't ignite after the combustion cycle, the electronic ignition systems probably need to be replaced. In cases where the furnace ignition starts normally but only stays on for a few minutes and then goes out, a new pilot light likely needs to be installed.
Can you DIY a furnace ignitor replacement? In short, yes, you can DIY a hot-surface ignitor replacement. It shouldn't be too difficult if you have experience fixing things around the house.
Like an extinguished pilot, a faulty ignitor prevents a furnace from heating up. Unlike pilots, electronic ignitors cannot be manually lit when they fail. However, a homeowner can take troubleshooting measures to determine if the ignitor is bad or if some other issue is causing the furnace not to blow hot air.
Most likely, your furnace is making a clicking noise and not providing heat because your furnace's spark igniter is trying to ignite your pilot light or burners but is failing to do so. In other words, there's an ignition system malfunction that needs to be fixed. Otherwise, your furnace won't start.
Remove the ignitor carefully by holding only the base. Avoid touching the ignitor surface with bare hands. Use compressed air to remove carbon deposits. Gently wipe the surface with a soft cloth or scuff pad until shiny.
A multimeter can be used to help determine if a glow-bar style furnace igniter has sufficient electrical continuity – a continuous electrical path present in the part – for the igniter to function properly.
The igniter glows red and then lights the burners in the gas furnace. Over time, the igniter is continually getting red hot and then cooling, creating stress on the element. Because of this, igniters have a 3-5 year life expectancy. They will eventually crack and need to be replaced.
If there is a strong draft in your basement or attic, or if you are experiencing high winds, the pilot light may not light. In addition, if your furnace has a draft motor or blower that is malfunctioning or dead, the pilot won't light. The purpose of the draft motor is to pull air into and out of your chimney or vent.
A furnace ignitor replacement costs $100 to $250 on average. Most universal hot-surface ignitor prices are $15 to $35 for the part alone. Gas furnace ignitor prices are $20 to $100 for parts from the original manufacturer (OEM). The labor cost to replace a heater ignitor is $80 to $200.
Check/Clean the Ignitor
A pilot ignitor coated in debris won't ignite the furnace, even if the thermostat clicks on and sends the right signal. To access the ignitor, remove the furnace's front panel. Identify whether the ignitor is dirty or clogged.
Pilot lights can also develop problems that cause them to burn inefficiently. When this happens, a small amount of carbon monoxide can be released into your home. Most gas appliances today rely on electronic ignition instead of inefficient pilot lights.
If you have a faulty furnace ignitor, it won't produce that tiny spark to heat the air coming from your Furnace. Your heater blows air at the same temperature as the cold outside air without it.
For instance, the flame sensor is on the left side, while the ignitor is located on the right side of the burners. When the burners produce a flame, the rod-shaped protrusion detects it and sends an electrical signal to the furnace's control board, signifying that everything is functioning correctly.
First, confirm the switch is in the "on" position, and if it is, see if your furnace starts up. If the switch is flipped down in the "Off" position, then your furnace will not turn on. If your heating system still does not start up, it might be due to a blown furnace fuse or tripped circuit breaker.
Gently rub the metal surface of the ignitor (the element for hot surface ignitors or wires for direct spark ignitors) with a scuff pad on all sides until it's shiny everywhere. Vacuum off all dust. Replace the ignitor, reconnect the wires and replace the panel.
If your gas furnace initiates the start cycle but doesn't fire up, it's likely because of a faulty, damaged, or dirty ignitor/sensor. This is a very common problem — you can try to clean the sensor and replace the ignitor.