All the more so on your ``sealed burner'' one where you REALLY can't see it. Use a stiff toothbrush, steel wool, a little oven cleaner, dish soap ... it doesn't matter. Just clean the thing without damaging it. It will spark back to life. :)
The Short Answer Is: Warning signs of a bad furnace ignitor include the furnace not starting or heating, a noticeable clicking sound without ignition, or frequent short cycling where the furnace turns on and off rapidly. Additionally, if the ignitor appears cracked or discolored, it may need replacement.
Reset The Furnace Ignitor
Find the burner door on the furnace and look behind it to find the ignitor. Turn it to “OFF” and wait for five minutes. After you wait, turn it back on and return the door to the burner. It is important to make sure the switch on the door is properly engaged.
If you can plug in a power cord and operate a screw driver, you can replace a broken gas furnace ignitor. It is a simple process of a couple screws and a plug. I walk through replacing this part and getting your furnace running again without a costly repair bill!
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.
If your furnace filter is dirty, it will block the airflow from reaching the heat exchanger. This will overheat your system, causing the ignitor to shut off. You will find the filter inside the blower compartment. Inspect the extent of damage and accordingly either clean it or go for a replacement.
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.
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 Average Furnace Lifespan
A well-maintained furnace can last at least 15 to 20 years, but completing annual maintenance and being diligent with repairs can extend its life even longer.
Using a paper clip or wire brush, clear any buildup or debris away from the mouth of the pilot light. Make sure nothing is stuck to the metal. Next, use compressed air to drive out soot and soil that may be deep inside the pilot light.
Problems with a gas furnace ignitor can be fixed using simple techniques. However, if the ignitor does not work at all, it will have to be replaced. Here's how you can repair your broken gas furnace ignitor.
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.
Hot surface ignitor Ð A hot surface ignitor resembles the filament wire in a light bulb. An electric current heats a small piece of metal until it's hot enough to combust the gas. Hot surface ignitors are typically the most common type of ignition system in today's gas furnaces.
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.
Checking your thermostat is the best place to start. Make sure it's set to “heat” and that you've set the temperature higher than the current room temperature. If that doesn't resolve the problem, try switching your fan to “on” to force the furnace to start working.
A heat exchanger that is overheated at shutdown could radiate extra heat on the ignitor to damage it or its ceramic base, especially in closed combustion systems like those Coleman or Intertherm downflow furnaces you find in modular and mobile homes.
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.
Most modern gas furnaces can be reset by turning off the power, waiting around 20 seconds, then switching the power back on. Other furnace models may exit lockout after 1-2 hours and attempt to power on again.