Why does my furnace keep trying to ignite?

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.

Why is my furnace clicking but not turning on?





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.

Why does my furnace come on when nothing happens?

If your furnace doesn’t switch on, the circuit breaker could be shut off. Check your circuit breaker panel to make sure all switches for your HVAC system are set to “ON.” Check Your Thermostat. If your furnace isn’t turning on, the thermostat may have lost its programming or reset.

How do I know if my igniter is bad on my furnace?

Here are a few indications that you have a faulty ignitor.

  1. No Cold Air. …
  2. The Furnace Won’t Come On. …
  3. The Furnace Suddenly Stops Blowing. …
  4. Starts, Then Stops, Then Starts Again. …
  5. Tripping the Breaker More Than Once. …
  6. I Hear the Click, But Nothing Happens. …
  7. Flame Sensor Problems. …
  8. Short Circuit.

How do I clean my furnace ignitor sensor?

Quote from the video:
Quote from Youtube video: So if you have a situation like this what you have 90% of the time is just a dirty flame sensor. So we'll go through the steps on how to clean it. So the right side of the furnace.

Where is the ignition sensor?





It’s located on the burner assembly and is just a thin metallic rod. It’s usually bent, and it sits just in front of the pilot flame inside the furnace.

How much does it cost to replace an igniter on a furnace?

Here’s the bottom line: Whether for a natural gas furnace, oil, or a propane furnace, replacing a furnace ignitor–including parts and labor–will cost you around $300 – $425 for a qualified contractor to install. Compare that to, say, a draft inducer motor, which will cost $400 – $1,500 to replace.

How do you test a spark ignition furnace?

Quote from the video:
Quote from Youtube video: Also set the dial to the lowest ohms of resistance to test for continuity take the probe from the multimeter. And touch it to one of the terminals. Now touch the second probe to the remaining.

How do I know if my flame sensor is dirty?

6 Signs of a Malfunctioning Gas Furnace Flame Sensor

  1. Yellow Burner Flames. Open up or glance through the peephole of your gas furnace to see the color of the flames firing up in the burner. …
  2. Rusted Flue Lines. …
  3. High Utility Bills. …
  4. Water Leaks. …
  5. Old Age. …
  6. Constant Thermostat Adjustments.



How often should a flame sensor be replaced?

Even if the flame sensor is in proper working order, it is advised that you replace it every two or three years as a preventative measure.

Can I bypass flame sensor?

Yes. You can bypass the flame sensor. However, if you do so, you can’t manually light your furnace, and you’ve got to have proper bypassing safety measures in place. But it’s advisable not to bypass the flame sensor.

Will furnace run without flame sensor?



If the flame sensor does not work, then the furnace will automatically shut down and stop the flow of gas. If there were no flame sensor and no flame, gas would continue to flow without being burned, and that’s setting up the house for a major explosion.

How does a furnace work without a flame sensor?

It’s a thin, metal rod that monitors the pilot flame. If the pilot flame goes out, the flame sensor will turn the unit off to prevent natural gas from leaking into the home. Without the flame sensor, if the pilot light goes out but the gas valve remains open, the gas will not burn and will seep out of the furnace.

Why do flame sensors fail?

What are causes of a dirty flame sensor? As with any piece of equipment a simple reason could be that dirty flame sensor just goes bad. However a more common reason is that it is just dirty. It is a sensitive sensor so any type of dust or carbon buildup could cause it to malfunction.

How much does a flame sensor cost for a furnace?

Flame Sensor



It stops your furnace from letting off large amounts of natural gas if it’s not working properly. If the sensor is bad, it won’t be able to sense heat and will turn the furnace off. The average cost to repair or replace a flame sensor is between $75–$200.

Can a flame sensor be intermittent?



The flame sensor is a safety component that detects whether or not there is a flame in the combustion chamber. If this sensor is dirty, the dirt can cause the sensor to operate intermittently. When this happens, your furnace will most likely light, but because the sensor can’t properly detect if a flame is present.