Why does the pilot light on my water heater keep going out?

Thermocouple Issues



If it senses that your water heater pilot light keeps going out, the thermocouple will shift off the gas supply to the heater. Over time, thermocouples can malfunction, accumulate dust buildup, or the device can get bent away from the pilot light’s flame.

Why does the pilot light on my gas heater keep going out?





A faulty, misaligned, dirty, or damaged thermocouple is often the culprit behind your pilot light going out. The thermocouple is an automatic safety shutoff device that prevents the gas valve from opening if the pilot light is out.

What does it mean when your pilot light won’t stay lit?

If your pilot light won’t stay alight, it might be the thermocouple. Sometimes dust buildup collects on the thermocouple and blocks the sensor. Try cleaning the thermocouple and then relighting the pilot light. If it continues to go out, the thermocouple might need to be replaced.

How do you fix a pilot that won’t stay lit?

Quote from the video:
Quote from Youtube video: You make sure that you don't use sandpaper or anything else that will leave other residue. So we're just using metal on this metal and that cleaned it off.

How much does it cost to replace a water heater thermocouple?

Thermocouple – $20 to $150



The thermocouple is an apparatus that senses whether the pilot light is lit and triggers the gas control valve. Repairs typically cost about $150 to have it done professionally, though a new thermocouple itself only costs about $20 on average.

How do I know if my thermocouple is broken?





If you can’t get the flame to light at all, and you’re sure the gas is on, there’s probably an obstruction in the pilot tube. If the flame lights and goes out when you release the gas control knob after holding it in for the recommended 20 to 30 seconds, that’s the sign of a thermocouple malfunction.

How do you clean a thermocouple on a water heater?

Clean the thermocouple – using the emery cloth sandpaper, sand the ends of the thermocouple and then give it a finishing touch with the lint-free cloth. Hopefully, you can get to the ends of the thermocouple without having to detach it from the assembly, but you may have to do that.

How do you clean a thermocouple on a gas heater?

In cleaning a thermocouple, you need some steel wool or 60-grit sandpaper, and a cloth. First, turn off the gas supply, unscrew the thermocouple and then clean it with steel wool or sandpaper then wipe down with a cloth to remove residue. I clean our thermocouple every six months to avoid getting it coated with soot.

Can a thermocouple be repaired?

Thermocouples are designed to detect a pilot light’s loss of heat and close the gas valve to prevent a gas leak. Replacing a thermocouple is a relatively easy fix that can take less than two hours.

How much does a thermocouple cost?



1 cause of pilot lights that won’t stay lit is a worn-out thermocouple. It’s easy to replace and a new one costs $5 to $10. Rather than trying to unfasten the thermocouple inside the water heater’s burning chamber, it’s easier to remove the whole burner and thermocouple assembly.

Does cleaning a thermocouple help?

Remove the thermocouple from the process assembly, using a steel wool or emery cloth, lightly clean the tip removing any build up. Cleaning a thermocouple is not a fix for an issue, such as inaccurate readings.

How long does a thermocouple last on a water heater?

How Long Should a Water Heater Thermocouple Last? If properly installed and maintained, thermocouples can last for up to 10 years.

How do you fix a bad thermocouple?



Quote from the video:
Quote from Youtube video: Use a soft abrasive pad or emery cloth to gently clean the outside of the thermocouple. Be careful not to scratch the coating. Next insert the thermocouple into the pilot assembly.

How do you bypass a thermocouple?

Quote from the video:
Quote from Youtube video: Okay that's the thermocouple here's a main igniter wire. And here is the tube that gives you propane. So you follow this wire down.

What can go wrong with a thermocouple?

Sudden loss of heat.



A faulty thermocouple will often “cut out” when it’s experiencing problems, meaning that it misinterprets the pilot light’s temperature and shuts off the gas. This can lead to your heater turning off unexpectedly, even though there’s nothing wrong otherwise.

How do I know if my thermocouple is bad on my water heater?

If the pilot lights but the flame goes out as soon as you release the button after holding it for 60 seconds, then the thermocouple is bad. It’s possible to replace the thermocouple without removing the burner assembly, and many repair people do this.

What is the most common thermocouple failure mode?



The most common failure mode for thermocouples is for them to fail open, this is known as thermocouple burnout. Burnout can result from a variety of reasons including the thermocouple experiencing a temperature in excess of that for which it was designed, metal fatigue, and oxidation.