Why does my flame sensor keep going out?

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 long should a furnace flame sensor last?





about 5 years

Note: According to HVAC.com, the expected lifespan of a flame sensor is about 5 years. Most furnaces last anywhere from 10 to 20 years. That means that you will have to replace a flame sensor 1x, 2x, or even 3x during a furnace’s lifespan.

What happens when a flame sensor fails?

Without a flame sensor, your furnace will keep emitting gas even when there’s nothing to ignite it, resulting in hazardous gas buildup. If your flame sensor is dirty or faulty, it will automatically shut down the heating unit if it doesn’t detect a flame.

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

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.

How often does a flame sensor need to be cleaned?





The service life of a furnace is 10 to 20 years on average. This means you’ll have to replace a flame sensor once, twice or three times over the course of the furnace’s life. Having a bad flame sensor is completely normal–you just need to know how to properly identify when it’s gone bad so you can replace it on time.

Can you bypass flame sensor?

You won’t find steps to bypass the flame sensor anywhere. While some furnace technicians claim to know how to do it on some furnaces (newer furnaces won’t allow it), there is no commonly understood way to do it.

How often do you replace a flame sensor on a furnace?

Because your furnace’s safety is of the utmost importance, it is always better to be safe than sorry and replace the flame sensor if it is malfunctioning. 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.

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

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.



What is the difference between a flame sensor and a thermocouple?

Thermocouples are used on standing pilot furnaces that have pilot lights. The thermocouple sits near the pilot light and gauges whether it’s working properly, while the flame sensor detects that the burners are lit once they start to emit gas and the igniters light them up.

How do you clean a flame sensor on a gas water heater?

How to Clean the Flame Sensor on Rheem Heaters

  1. Step 1: Power Down the Furnace. Switch off the furnace switch. …
  2. Step 2: Locate the Flame Sensor. Remove the access panel. …
  3. Step 3: Remove the Flame Sensor. …
  4. Step 4: Clean the Probe. …
  5. Step 5: Replace the Flame Sensor. …
  6. Step 6: Test the Sensor.



How much does it cost to clean furnace flame sensor?

If they are part of a routine maintenance service, they will cost about $200. Similarly, flame sensors often become too dirty and malfunction, but these sensors can be fixed with a thorough cleaning. However, if it’s too far gone and you must replace the flame sensor, it will cost you anywhere from $80 – $250.

When should I replace my flame sensor?

Once you clean off the sensor properly, it should go back to functioning like it’s supposed to. Unless the flame sensor is physically damaged or broken, you typically won’t have to replace it. They last a fairly long time, so most issues involved in the part not working right usually boil down to a fixable error.

Can you clean a furnace flame sensor?

Once you have removed the sensor, gently rub the metal rod (and nothing else) with a very light grit sandpaper. Remember, you’re not sanding down an auto body here, just ridding the sensor of any buildup. Then, use a clean paper towel to wipe clean any dust left behind by the sanding.

How do you replace a flame sensor on a water heater?



Quote from the video:
Quote from Youtube video: Before you install the new igniter in flame sensor peel off the old insulation from the burner. Cover. Apply some high-temperature adhesive then align the new insulation on the inside of the cover.

How do you change a furnace flame sensor?

How to Replace an Electronic Flame Sensor

  1. Locate the Flame Sensor. Remove the furnace’s access cover. …
  2. Remove the Flame Sensor. Disconnect the electrical wire leads to the sensor. …
  3. Install the New Flame Sensor. Install the new flame sensor in the same position as the old part and secure it with the screws.


How long do furnaces usually last?

15 to 20 years



A well-maintained furnace can last at least 15 to 20 years, but completing annual maintenance and being diligent with repairs can extend its life even longer.

Are all furnace flame sensors the same?

– This symptom is often caused by a dirty flame sensor that can be easily cleaned. 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).

How much is a new furnace?

A new furnace costs $1,500 to $6,500, depending on the model you choose. The average cost of installing a mid-efficiency furnace is $1,500 to $2,500. Mid-efficiency furnaces have an annual fuel utilization efficiency (AFUE) rating of 80% to 89%.

How much is a new furnace for a 1500 square-foot home?

between $2,990 and $4,360

The average cost to replace a gas furnace in a 1500-square-foot house is between $2,990 and $4,360. For a standard-efficiency gas furnace, a 60,000-80,000 BTU model is the best choice.

How much is a new furnace for a 2000 square-foot house?

The average cost range for purchasing and installing a gas furnace designed to heat a 2,000-square-foot home with a 97% efficiency rating ranges from $4,000 to $8,000, with most homeowners spending around $6,000 total on a high-efficiency gas furnace replacement in a 2,000 sq. ft.