How do you test a bad ignitor?

Here are a few steps to check your ignitor and determine if it needs to be replaced.

1. Make Sure The Furnace As At Room Temperature.
2. Turn Off The Furnace.
3. Switch Off Circuit Breaker.
4. Remove Furnace Service Panel.
5. Look For Visible Damage.
6. Remove Ignitor Wires From Socket.
7. Test The Ignitor With A Multimeter.

What causes a hot surface ignitor to burn out?

A furnace control board where the ignitor relay on the control board is stuck closed and keeps the ignitor burning all the time. Debris from the heat exchanger or bugs/spiders can get on the ignitor while the furnace is not calling for heat and when there is a call for heat the debris/bug can short the ignitor out.

What causes an igniter to 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 does a hot surface igniter do?

Hot surface ignitor are the most commonly used electronic ignition system. It works like a light bulb filament, heating up when electricity is passed through it. Most are made from silicon nitride or silicon carbide ceramic. When the gas valve opens, the gas is ignited by the igniter.

What happens when flame sensor goes bad?

What happens when a flame sensor goes bad? If your flame sensor is dirty or faulty, it will automatically shut down the heating unit if it doesn’t detect a flame. Most furnaces will go into a safety ignition lockout when a shutdown happens three times.

Do furnace ignitors go bad?

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.

Can a furnace ignitor be cleaned?

Check the Ignitor Sensor If you think that this could be the problem, the ignitor sensor needs to be cleaned. To clean the ignition sensor, turn off your furnace’s power supply. Once you’ve cleaned it, replace the sensor and the screw, and your furnace should start working again.

What is the temperature of a hot surface ignitor?

Hot Surface Igniters are Resistance Heaters A 120-volt HSI will glow at around 2500 degrees Fahrenheit. Most gas fuels will ignite around 1100 degrees, so 2500 degrees is a little excessive. A 240-volt igniter burns even hotter.

What is the difference between spark ignition and hot surface ignition?

Direct Spark ignition systems include a spark electrode/flame sensor, gas valve, and ignition control. It generates a spark to ignite the burner. Hot Surface Ignition makes use of a silicon carbide igniter that is heated to a red-hot condition. This silicon carbide element then lights the main burner.

How do you know if your flame sensor is dirty?

How do I know if my furnace flame sensor is bad?

1. Switch off the power to your furnace.
2. Close the gas valve.
3. Take out the mounting screw.
4. Carefully pull out the sensor.
5. Inspect the sensor: if the insulation is intact but appears sooty, burnt or slightly corroded, it might only require cleaning.