Do all furnaces have a flame sensor?

Not all furnaces have a flame sensor, but if your furnace has one, it will be mounted close to the burner with the metal rod positioned in the flame. Flame sensors vary in size (2 to 4 inches) and shape (see examples below).

Can you bypass a furnace 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.

Why is my pilot light on but no heat?

If there’s a pilot light, make sure that it’s lit and touches the thermocouple. If it’s lit but the burners don’t heat, feel the side of the furnace. If it’s cool, the problem might be the thermostat, gas valve or control board. Make sure that the gas valve is on and that there’s enough fuel.

Is a thermocouple and flame sensor the same thing?

People tend to use the terms “flame sensor” and “thermocouple” interchangeably. In truth, while they basically perform the same job, they’re not the same thing. If your furnace uses an electronic controller, it’s got a flame sensor. Thermocouples are used on standing pilot furnaces that have pilot lights.

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 is my furnace not igniting?

If your gas furnace initiates the start cycle but does not fire up, it’s likely because of a faulty, damaged, or dirty ignitor/sensor. This is a very common furnace problem—you can try to clean the sensor and replace the ignitor.

Why is my flame sensor not working?

Quote from Youtube video: Board if this is loose or broken. Off sometimes that will cause your flame sensor issue as well so you clean up your flame sensor you plug it in but it's still doing the same problem.

How do you bypass an ignition sensor?

We have a different solution:

  1. Remove the access cover on the furnace.
  2. Locate the flame sensor.
  3. Cut the power to the furnace.
  4. Shut off the gas control valve.
  5. Take out the flame sensor by removing the mounting screw.
  6. Examine the part to see if it’s compromised, either by damage or dirtiness.

How do you test a furnace flame sensor?

Quote from the video:
Quote from Youtube video: And connect one of the probes. Coming off the meter to the wire that you just disconnected. You're going to stick the probe between the insulation. And the back of the clip.

Is flame sensor same as Ignitor?

It is a rod that sticks out where the flame comes out of the burner. The flame sensor is always on the opposite side of the ignitor. For example, if the ignitor is on the right side of the burners, then the flame sensor is on the left side.

Should thermocouple be in pilot flame?

The pilot flame should touch the thermocouple at a specific level. If the flame is blue and weak, and barely reaches the thermocouple, it needs to be stronger. If it extends well above the thermocouple, it’s too strong.

How much does it cost to replace a flame sensor on a furnace?

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 I clean a flame sensor?

Quote from the video:
Quote from Youtube video: Now there's the flame sensor. And all we have to do to clean this is just to take a little piece of Emery paper. And sand it slightly. So if you don't have any of the sand.

How do you know if furnace sensor is bad?

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.

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.

What does a faulty flame sensor look like?

Signs of a bad furnace flame sensor are: The furnace lights but then shuts down after a few seconds (short cycles) The porcelain on the flame sensor is cracked. The flame sensor is sooty or corroded.

What does a flame sensor do on a gas furnace?

A flame sensor is a crucial safety component on your gas heating system. During the ignition cycle, your gas furnace goes through a process where a spark or a hot surface ignitor will actually ignite the gas. As the gas is ignited, the flame sensor creates a current of electricity.

What should furnace flame look like?

Your natural gas furnace’s burner flames should be almost totally blue. The sign of a good natural gas furnace, according to heating service professionals, is a roaring blue flame with a light blue triangle in the center. A sliver of yellow may also be present.

How do you reset the flame sensor on a furnace?

Quote from the video:
Quote from Youtube video: That's holding a little bracket on the top. And we're going to remove the thermocouple and we're just going to take a little sandpaper. Actually the best is an Emery cloth.