Gas Water Heater Thermocouple Test
The thermocouple is a vital safety feature for many gas appliances.
Gas water heater thermocouple test. With the leads apart you will read infinity. Use a small flame source to test a thermocouple with a multimeter. Finally now turn the meter to volts. For testing a thermocouple you first have to remove it from the furnace water heater or gas appliance where it is installed.
The burner typically sits loosely or under clips in the burning chamber and just slides out. Light the pilot by pressing and holding the pilot light button on the gas control valve. 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. A thermocouple is a safety device that helps control the gas supply in gas heated furnaces.
You can test this yourself using a multimeter but you may need a helper to keep the pilot flame burning while you do it. Once it is removed you will need a multimeter that needs to have the ability to read millivolts and a source of fire. For a basic test attempt to turn on the pilot light again. When it stops working the furnace s pilot light also turns off.
If you can t light the pilot the problem most likely lies with the gas control valve or the gas flow itself not the thermocouple. Diy hot water heater repair. Secondly turn on the meter and set it to ohms. First remove the thermocouple.
It is comprised of two different types of metal which react differently to heat and expand at different rates signaling to the water heater when to turn on or off. Gas appliance thermocouples have a standard design. How to test a thermocouple. Touch the two leads together from the meter and you should get a reading close to zero.
Usually a lighter will suffice for the test. Measure the current by using the multimeter device set on millivolts. The water heater thermocouple is a device that monitors temperatures in the water heater to determine whether it needs to heat up or turn off the heat. A thermocouple uses the heat from a flame to produce a millivoltage that controls a gas valve.
Here s how to test a suspected thermocouple in a gas operated water heater. If you re still unsure or don t have a working pilot light test the thermocouple with a multimeter. One probe of the meter should be connected to the copper sheath of the thermocouple and the other to the gas valve. Multimeter thermocouple test procedure.
Then unfasten the three nuts that hold the thermocouple and the two gas tubes to the valve. 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.