How to test a thermocouple with a multimeter.
Gas water heater thermocouple test.
The thermocouple will be located right next to the pilot.
The thermocouple is part of the pilot assembly where one end is always in contact with the pilot flame while the other side is connected to the gas control valve.
Thermocouples designed for residential gas appliances such as fireplaces water heaters and furnaces are made for 30 millivolts.
Then unfasten the three nuts that hold the thermocouple and the two gas tubes to the valve.
The burner typically sits loosely or under clips in the burning chamber and just slides out.
A thermocouple is a safety device that helps control the gas supply in gas heated furnaces.
Diy hot water heater repair.
How to test a thermocouple for a water heater everyone who has owned a gas heater including furnaces or water heaters will know that from to time you have to light the pilot light unless you have the electronic ignition that automatically lights the pilot light.
A gas water heater in boise baton rouge buffalo or boston uses a thermocouple that includes a probe attached to a copper tube that screws into a port on the gas valve.
Take the thermocouple to the store and replace if needed.
You know you have a problem.
This is a safety device whose purpose is to monitor the pilot light and send a signal that shuts the gas burner valve should the pilot.
For a basic test attempt to turn on the pilot light.
How to test a thermocouple.
Anything under or hovering around the 20 millivolts mark means the thermocouple needs to be replaced.
The reading should be between 25 and 30.
Turn off the gas to the water heater and remove the thermocouple from the water heater.
When it stops working the furnace s pilot light also turns off.
Importantly always make sure the tip of the thermocouple is directly in the pilot flame.
If you test the thermocouple with the multimeter and you get a reading above 25 then you have another issue.
If the thermocouple is working you should be able to measure 30 to 40 millivolts of voltage at the connection end of the tube when the pilot flame is on.
Install the new thermocouple turn on the gas and light the pilot.
Sometimes when you try to light the pilot it does not want to stay lit.
Inside your gas operated water heater is a tiny gas flame called a pilot light whose purpose is to ignite the burner whenever the temperature falls below the thermostat setting.
