How to bypass flame sensor on furnace

How to bypass flame sensor on furnace. When your furnace has no flame, the problem might not be what you imagine it is. Whenever furnaces don’t work correctly, it’s mainly due to a malfunctioning flame sensor.

Whenever your furnace or heater doesn’t turn on, you should realize that a malfunctioning flame sensor is most likely to blame. A faulty flame sensor prevents the furnace from igniting.

This is why understanding how to fool a flame sensor would not help anyone. You may, however, keep your furnace up and running again by ensuring that the flame sensor is in excellent working order.

How to bypass flame sensor on furnacehow to bypass flame sensor on furnace (guide)

In the section below, we’ve covered what you should do if you thought you needed to bypass the furnace’s flame sensor.

The following information will assist you in quickly repairing your furnace.

We’ll show you how to fool a flame sensor with a few different methods. You will learn everything about it in this article. So continue reading.

How to know if Your Flame Sensor Is Faulty

The first method in enabling the furnace to perform is to check if the furnace flame sensors have failed.

  • Examine the flame sensor to see whether it is rusted.
  • The furnace will turn on for a short time before shutting off. The following are the most prevalent symptoms of a malfunctioning flame sensor:
  • Examine the flame sensor for any signs of cracking. Porcelain
  • ‘Shutdown Mode’ will be activated on the furnace.
  • The furnace won’t turn on at all.

Cleaning a Flame Sensor

Knowing how well a flame sensor works will help you understand why overcoming it is a poor decision. Cleaning the flame sensor will usually solve all of your problems.

As a result, rather than replacing the flame sensor, consider cleaning it. This is how to clean a flame sensor simply:

  • You switch the furnace down, switch off the breaker or the power.
  • Properly close the control valve.
  • Unplug the cable which is linked to the flame sensor afterward.
  • Next, use a Philips screwdriver, and remove the flame sensor from the burner housing.
  • Next, wash the darkened rods of the flame sensor with a covered abrasion, including such abrasive cloth.
  • Gently wipe each flame sensor with a clean piece of cloth.
  • To use another clean cloth, clean the flame sensor socket.
  • Return the flame sensor to its original location.

What Is the Best Way to Inspect a Flame Sensor?what is the best way to inspect a flame sensor

If cleansing the flame sensor doesn’t function, check to determine if the flame sensor is in good working order. A faulty detector would almost certainly not function. This is how to examine a flame sensor quickly:

  • Get a multimeter that measures microamps (A).
  • Maintain the furnace system’s operation.
  • This should be connected to the cable that leads towards the gas valves.
  • Attach the multimeter’s second end to the sensor terminal.
  • Remove that wire out from the flame sensor.
  • Attach the wire to one of the meter probes.
  • The other connection should be connected to the sensor terminal.
  • Set the thermostats to the desired temperature.
  • Analyze the results of the multimeter.

If the flame sensor is working correctly, your multimeter will read 5 to 10 amps. A defective flame detector may offer you a reading that is lower than this.

How to Replace a Flame Sensorhow to replace a flame sensor

If the flame sensor analysis indicates that you have a faulty flame sensor, you should replace it immediately. This is how to repair a flame sensor in your furnace quickly and comfortably:

  • Switch off the furnace.
  • Allow half an hour.
  • Remove the furnace access cover to get to the flame sensor.
  • Disable the flame sensor’s connections to the control box by removing all of the flame sensor’s connections and wires.
  • Uninstall your flame sensor with a Phillips screwdriver.
  • Replace the old flame sensor with a second unit.
  • Customize the wires after you’ve screwed them in place.

Cost to replace flame sensor on furnace

Having your chimney cleaned out in the fall or early spring will cost about $200. If you choose to have flame sensors checked, it’s best to do so when they are in good working order.

When getting it fixed, there must be no contact between wire and ash unless the flame sensor is being replaced. This will cost either $80–$250, depending on what needs to be done for your specific circumstances.


How to bypass flame sensor on the furnace. A flame sensor working in the furnace is an essential part of this article. We have gone through significant problems about bypassing the flame sensor on the furnace and providing you guys with the best fixes for it.

Troubleshooting the Flame Sensor

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