How to Fix the Ignitor Problem on a Furnace
- Turn the power off to the furnace by turning the emergency switch to the off position. ...
- Open the burner access door by lifting up on the door handle and pulling the door away from the furnace.
- Disconnect the wiring harness from the igniter. ...
- Use a nut driver to remove the two hex head screws that secure the igniter to the furnace. ...
Full Answer
How to check if your furnace Ignitor is bad?
Volt Meter Method
- Shut off the power to the circuit for the furnace at the breaker box. Open the furnace and locate the ignitor following the instructions from the furnace's manual.
- Remove the plug at the end of the ignitor.
- Attach the leads from the volt meter to the ignitor plug.
How do I manually turn on my furnace?
- Switch OFF the furnace at the breaker.
- Open the furnace access door and locate the circuit board.
- Locate the main fuse. ...
- Take it out and inspect it for damage using a flashlight. ...
- Purchase a replacement if the fuse is blown. ...
- Insert the replacement, making sure it fits snugly.
- Now, switch the breaker ON and turn on the furnace to see if it works. ...
How to fix flame sensor on furnace?
Where is the Flame Sensor on the Furnace?
- Disconnect the furnace: Never attempt to access the burner area with the furnace running. ...
- Allow the furnace to cool: The internal components will be very hot if the furnace runs for more than 10 minutes. ...
- Remove the burner compartment door: This process varies from one furnace model to the next. ...
How to fix a noisy furnace blower?
The Furnace Blower Motor Makes Noise
- Fasten the Motor With Bolts. Fastening the motor with bolts and installing rubber mounts can help alleviate the issue of a furnace blower that is too loud.
- Lubricate the Bearings. Lubricating the bearings drastically reduces the chances of them wearing. ...
- Replace Loose Parts. The wear and tear of the fan motor can cause the fins to loosen. ...

How do I know if my furnace ignitor is bad?
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. Cold air blowing through your vents is a good sign that you have a heating problem within the Furnace.
Can you clean a furnace ignitor?
If your furnace has a spark ignitor and it's working haphazardly, it too could be covered with soot, and a blast of compressed air may be enough to clean it. Compressed air can also clean a blocked pilot tube that is causing the pilot flame to burn weakly or not at all.
What causes furnace ignitor failure?
As mentioned above, sometimes the cause of a furnace ignitor failing to ignite is due to a safety issue, such as a clogged air filter, for instance. Air filters should be changed on a regular basis, to prevent these kinds of problems. However, a lot of furnace owners fail to do this.
Why is my furnace ignitor not glowing?
On most furnaces the ignitor will not glow unless all the safety controls (limit, rollout switch/switches, pressure switch) are closed. If a limit or rollout switch is open, you can have an overheating problem and a possible dangerous condition. You may need to replace the limit switch or rollout switch.
Can hear your furnace click on but it does not fire up?
You Have a Faulty Ignition Sensor (Pilot Light) The pilot light or ignition sensor is usually the most common issue when your furnace will not ignite. This is typically the problem if you can hear your furnace click on but it does not fire up.
How much does it cost to replace a furnace ignitor?
A ballpark figure is approximately $75 to $100. This cost covers only labor. At times, parts and services can go up to $250 to $300. Remember that your unit will not turn on if your furnace igniter malfunctions, despite having just replaced the part.
Can I manually ignite my furnace?
Never attempt to light a furnace by a flame manually, especially if the furnace has an electronic igniter. A furnace equipped with an electronic igniter cannot be lit manually. Call for the services of a professional heating and cooling technician when the igniter is not working properly.
What causes an igniter to go bad?
High Voltage An 80-volt HSI should have about 80 volts applied to it. Applying 120 volts to that HSI will cause it break, and sometimes almost immediately. Having too low of voltage may not let the igniter burn hot enough.
Why do hot surface ignitors go bad?
Most of the time when ignitors go bad that often it is because the ignitor is not shutting off after the gas in the furnace is ignited. If the ignitor stays on for an extended period of time this will make the ignitor short-lived.
What controls the igniter on a furnace?
A sensor detects the activity and opens the valve that leads to the burners. The pilot light then ignites the burners. The hot surface ignition type, however, uses electrical power to heat up the area. After the system reaches a specific temperature, gas will flow to the burner and light up the ignitor.
How do you bypass the flame sensor on a furnace?
But how to bypass flame sensor on furnace? You can do this by removing the furnace's access cover, identifying where the flame sensor is, then disconnecting the furnace from the power source. After that, switch off the gas control valve, remove the flame sensor, and check where the problem is.
Can you clean an igniter?
Use the toothbrush and a paste of baking soda and water or a 50/50 vinegar solution to clean the surface of the igniter. Avoid cleaners with bleach, ammonia or any other chemical that could produce noxious fumes. If you have to chip material off it, use a plastic toothpick or kitchen knife.
Can a hot surface ignitor be cleaned?
It is not necessary to clean a hot surface igniter as it blow off any dust. However contrary to silicon carbide ceramic hot surface ignitor which are very brittle and shouldn't be touched, silicon nitride hot surface ignitor are very robust and can be cleaned manually iff really necessary.
How do you clean an oil furnace ignitor?
Gently pull the fuel nozzle and igniter out of the furnace with both hands and set it on a clean, flat surface. Spritz the tip of a clean cloth with an all-purpose cleaner spray and clean off the cowler, as well as any screws or bolts attached to the nozzle.
How do you clean a dirty flame sensor on a furnace?
Once you have removed the sensor, gently rub the metal rod (and nothing else) with a very light grit sandpaper. Remember, you're not sanding down an auto body here, just ridding the sensor of any buildup. Then, use a clean paper towel to wipe clean any dust left behind by the sanding.
How to check if a furnace is noisy?
Turn the power off on the furnace. Check the pilot light, and see if it lights properly. The light may go out repeatedly or may not work at all. This indicates a problem with the thermocouple. If the pilot light is working normally, but the furnace is noisy, the furnace may need minor repairs. Also check the air filter; if it is dirty, clean it. Clean the blower blades and lubricate the motor. Finally, inspect the belt attached to the motor.
What to do if your thermocouple is not working?
After you have cleaned the pilot orifice, check the thermocouple for any visible damage. If the thermocouple is not working properly, you may need to replace it . Adjust the pilot once again and set it at a higher setting.
How to Troubleshoot Your Furnace Ignitor?
The first thing you should do is turn your furnace switch off. And then remove the doors of the furnace.
How to replace your Furnace Ignitor?
The first thing you should do is turn your power switch off. Because you don’t want to operate furnace while the power is running. It can be fatal if you do that.
Furnace not igniting because of incorrect thermostat setting
Many homeowners forget they need to change their thermostat setting back to ‘heat’ or ‘heating’ after a mild fall. An accidental change or power outage could also mean you need to reset your thermostat to your preferred setting. Before we get into more difficult fixes, check your thermostat.
Furnace not igniting burners due to tripped circuit breaker or blown fuse
It is possible a tripped circuit breaker or blown fuse may be the underlying reason your furnace is not igniting properly. Though this may seem like too simple a problem, rule it out before proceeding.
Gas furnace will not ignite because of a faulty gas line
A faulty gas line could be the reason your gas furnace is not lighting. First, check and make sure that your gas is turned on. Your shut-off valve should be outside and will resemble a rubberized strip of metal about five inches long. If it is perpendicular to the gas pipe then it is turned off. If it is parallel with the gas pipe, it should be on.
Gas or oil furnace not igniting because of dirty burners
Dirt or grime on the burners themselves can restrict the flow of air and prevent the burners from lighting. If the burners look dirty, you can try cleaning them to get them to ignite.
Furnace maintenance tips
To ensure your furnace runs smoothly when you need it to, follow these maintenance steps throughout the year.
How to know if you need a repair vs replacement?
A professional HVAC technician will tell you if it is time to replace your furnace system. Some tell-tale signs, however, include:
Is this something I can fix myself?
It depends on your comfort level removing burners and replacing electronic ignitions. If that is something you are comfortable with, you may be able to fix it yourself. In many cases repairing a furnace is a job better suited for a licensed professional so that you know it is being done right.
How to tell if the furnace ignitor is bad?
Before diagnosing the gas furnace ignitor as the source, check your thermostat to ensure you have the setting switched to heat. If so, then the ignitor isn’t creating the combustion needed to warm the air.
Where to buy a furnace ignitor?
If you or a qualified technician determine the furnace ignitor is the culprit, then you can pick one up from a local hardware store. Your furnace manual includes information on the correct model to buy. You can also check with your retailer, who can look up that information.
Why does my furnace ignitor stop working?
Another reason your ignitor quits working is it receives too much power. If you notice your breaker box trips every time your furnace turns on, it means your ignitor cannot handle the power load. Find a local electrician to inspect and repair the problem.
Why does my furnace not start?
If you hear the furnace click on but it never fully fires up to begin the heating cycle, a faulty furnace ignitor is likely to blame. In this situation, the furnace detects there’s a problem (often with the ignitor’s inability to create a combustion) and shuts down to keep you safe. Call your local furnace technician to perform a furnace ignitor replacement.
What temperature does a furnace ignitor go to?
The ignitor sits beside the gas burners, and when the thermostat communicates that it’s time to distribute warm air, the hot surface ignitor can reach 2500 degrees Fahrenheit.
Why does my furnace keep turning on and off?
When this happens, the furnace detects something is wrong, and as a safety measure, shuts it off.
Why does my furnace make a clicking noise?
When you turn up the thermostat to initiate your furnace, you might notice a clicking sound before the warm air arrives. That noise comes from the furnace ignitor.

Step 1 – Inspect The Pilot Light
Step 2 – Inspect The Electrical Service Panel
Step 3 – Inspect The Thermocouple
- After you have cleaned the pilot orifice, check the thermocouple for any visible damage. If the thermocouple is not working properly, you may need to replace it. Adjust the pilot once again and set it at a higher setting.
Step 4 – Lighting The Pilot
- Check the control knob and set it on pilot. Hold a match under the gas port of the pilot. Press the control knob and see if the pilot lights are on. Hold the knob down until the flame begins to burn brightly. Slowly release the pressure and turn to the on position.
Step 5 – Replacing The Ignitor
- If none of these techniques works, you will have to replace the ignitor. Turn the furnace off and open the access door. Disconnect the wiring harness by pressing on the tabs that hold the wiring. Using a screwdriver, remove the hex screws that hold the ignitor to the furnace. If the ignitor is broken or badly discolored, it will have to be replaced...