How does electronic ignition work on gas furnace?

Author: Mr. Dexter Jaskolski V  |  Last update: Tuesday, June 16, 2026

This is the most common type of ignition in modern furnaces, and it works similarly to an incandescent light bulb. An electric current runs through a metal probe positioned over the burners, and the current causes the probe to turn hot the same way filaments in a light bulb glow hot when current runs through them.

How do you reset the electronic ignition on a furnace?

How to Reset an Electric Furnace
  1. First, turn off the power supply to the furnace by turning off the breaker in the circuit box.
  2. Locate the reset button on the furnace and press it to reset the furnace. ...
  3. If the button is popped up, press it down.
  4. Return the cover to the blower compartment and turn the power on.

How do I know if my gas furnace ignitor is bad?

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.

What can go wrong with electronic ignition?

Common electronic ignition issues:

Bad wiring or outlets: Electronic igniters can suffer from the same troubles as any electric system; crossed wiring at the junction box or issues with the outlet powering the ignition can cause it to stop working.

Can you manually light a gas furnace with electronic ignition?

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.

Gas Furnace Training- Intermittent Pilot Ignition: Gas Valve, Spark, Module, Operation, Testing!

How does electronic ignition work?

An electronic ignition system operates within electronic circuits, typically utilising transistors that are controlled by sensors to generate electric pulses. These pulses, in turn, produce a high-voltage spark capable of igniting the lean mixture in the engine, resulting in improved fuel economy and reduced emissions.

How do I know if my electronic ignition is bad?

The symptoms of a bad ignition control module and a bad distributor module overlap significantly, but some common signs that may indicate a bad distributor control module include engine misfires, difficult starting or no start, stalling, rough idle, poor fuel economy, lack of power and acceleration, and increased ...

What is the most common ignition problem?

Common Ignition System Problems

One of the most common is a dead battery. If your battery dies, your vehicle won't have enough power to start. Other common problems include a faulty starter, a bad ignition switch, a faulty distributor, and worn spark plugs.

What are the disadvantages of electronic ignition?

High Energy (Electronic) Ignition System

Also, the ignition timing cannot be as precisely controlled as with more sophisticated systems, resulting in poor fuel efficiency and lethargic acceleration.

Why is my furnace turning on but not igniting?

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.

Will a furnace run with a bad ignitor?

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.

Where is the reset button on the furnace?

Typically, you'll find it inside the air handler, either next to or above your furnace. In most newer systems, the button is often directly next to the blower motor, while in older systems, it may be harder to spot as it is sometimes underneath or behind the motor.

Can hear your furnace click on but it does not fire up?

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.

Can a thermostat cause a furnace to not ignite?

Furnace Not Igniting Because of Incorrect Thermostat Setting

Make sure the thermostat is set to heating and that the temperature is set high enough to actually turn the furnace on. It may be set at too low of a temperature to activate the furnace.

Can electronic ignition fail?

Many newer cars these days have fobless ignitions, which means that your EIS (electronic ignition system) could be failing. You'll need to seek diagnostics, especially if you have limited symptoms. EIS modules, steering lock modules, and gateway modules can also cause issues with starting your vehicle.

How to solve an ignition problem?

Quick Fixes
  1. Pull the key out slightly and try to crank the ignition. ...
  2. Clean the key if it looks dirty or greasy. ...
  3. Wiggle the key gently back and forth as you turn it. ...
  4. Slide the key in and out a few times. ...
  5. Get a new key cut if the pins are totally worn out.

What are the symptoms of a bad ignition switch?

Symptoms of a Failing Ignition Switch
  • Key is hard or impossible to turn in the ignition. ...
  • Engine won't crank. ...
  • Engine starts and stalls. ...
  • Electrical issues or inoperative accessories. ...
  • Stalling when driving.

How do I know if my electric igniter is bad?

Signs of a Faulty Ignitor
  1. Short-cycling: your furnace turns ON and OFF.
  2. Cold air: your furnace blows cold instead of warm air.
  3. No air: your furnace doesn't produce any air.
  4. Short-circuiting: your furnace keeps tripping the breaker.
  5. Unusual activity: your furnace produces strange sounds and smells.

Does electronic ignition replace distributor?

When converting from points to electronic ignition, you've got two options. You can either convert your existing distributor, or you can install a new distributor.

How do I know if I need a new ignition system?

8 Signs of a Faulty Ignition Coil
  1. Your Car Guzzles Gas. ...
  2. Your Car Feels Slow. ...
  3. You Hear Spluttering, Coughing, and Banging Noises. ...
  4. Your Car Idles Roughly and Vibrates. ...
  5. Your Car Misfires and Backfires. ...
  6. Your Car Stalls. ...
  7. You Struggle to Start Your Car. ...
  8. The Check Engine Light Is On.

How to know if electronic ignition is bad?

Proper functioning of the electronic ignition system is crucial for the overall performance and efficiency of the engine. When the system malfunctions, it can lead to various issues such as misfires, poor fuel economy, difficulty starting the engine, and even engine stalling.

Do gas furnaces have electric ignition?

Most natural gas furnaces have changed over to using electronic ignition systems instead. The reason for the change is to make furnaces more energy-efficient as well as more reliable.

Can you replace an ignition switch yourself?

You can replace the ignition switch yourself, but it's not an easy task: you will have to remove the steering wheel and work close to the airbag - which can be dangerous. Don't hesitate to call a professional mechanic if you're not feeling confident.

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