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A Bad Thermocouple Can Cause No Hot Water in Your Home

The water heater thermocouple is a sensor in your system that controls the gas valve. When the thermocouple isn't working, a few things can happen: the water heater pilot light won’t stay lit, your home can lose hot water— or you can even experience a gas leak, which will cause a gas smell in your house.

Checking For A Bad Water Heater Thermocouple

A thermocouple is a small sensor with a big responsibility. When your gas water heater's pilot light turns on, it triggers the thermocouple to release a small electric current, which then allows the gas valve to open.

If the thermocouple breaks, the gas valve won't know whether to stay open or closed. In turn, your water heater pilot light won’t stay lit, which can cause your water heater to malfunction, and the unburned gas could leak into your home.

How To Check For A Bad Thermocouple

  • Gas can be serious business. If you can smell gas in the air, open some doors and windows to vent it out of the room. Do NOT use a fan to blow the gas smell out. An electrical spark in the motor could ignite the fumes. After opening the doors and windows, clear everyone out of the house just in case. Check back occasionally to see if the gas fumes have cleared. If you can still smell gas or it's gotten worse, it's time to leave and shut off the gas at the main valve. After the valve is shut off, call the gas company and let them know. They'll be able to help.

  • Check the gas line that is going to the hot water heater. The valve on the line should be in the "on" position. It's "on" when the handles of the valve are lined up with the pipe (parallel). If the valve has been bumped or turned off, simply turn it until it is back inline with the pipe.

  • Try lighting the pilot light while holding the safety button down for about a minute. Repeat the process a couple of times if the pilot light won't stay lit. If the pilot light stays on as long as you hold the button down but goes out as soon as you release it, that's a sign that the thermocouple isn't working. It'll need to be replaced.

If a broken thermocouple isn't the problem, you can investigate other causes of no hot water.

What To Do If You Have a Bad Thermocouple

If the problem with your water heater seems to be your thermocouple, address the issue as soon as possible. You should contact a technician who can make sure the problem doesn't lead to more serious consequences.

NOTE: This content is for informational purposes only, and HomeX and its affiliates disclaim all liability related to it. If you decide to perform any tasks based on this information, you assume all risks, including the risk of loss or damage to property or personal injury.

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