How To Check A Hot Water Heater Thermostat With A Multimeter

If the reading shows the value of 240v then the power is on.

How to check a hot water heater thermostat with a multimeter. The multimeter readings ought to be ranging between 220 and 240 volts. At the bottom of the electric water heater remove the metal plate to show the thermostat you suspect is faulty. If it is you will have a reading of 240v on terminals 1 and 3. If there is now reading on the multimeter you have a faulty upper thermostat.

If the water is hot enough at appointed temperature the multimeter will point near zero. But if there is no reading check its power source. Leave the upper thermostat in the lowest setting and test the lower thermostat. Now check the lower thermostat.

Place the remaining probe against the metal base attached to the element where it enters the water heater. If the water is hot enough at appointed temperature the meter won t show reading. Below are the steps to follow when measuring the current of an electric water heater thermostat using a digital multimeter. If the reading shows zero then it s safe to proceed.

If the water is cold the multimeter will point near zero. Place the prongs of the multi meter on the terminal 1 and red wire of the lower heating element. To view all our multimeter ranges go to http bit ly 1edndeo in this video josh shows us how to use a multimeter to check for faults in a thermostat. The element is bad and must be replaced if the needle on the face of the multimeter moves.

Touch one probe of the multimeter to each terminal on the lower thermostat. Now to check the lower thermostat you need to set the dial of the upper thermostat to the minimum and set the lower thermostat to the highest. If the opposite thing happens that means your thermostat has defected. Connect the multimeter pin ends on point 1 3 as shown in the picture below.

The lower thermostat has only two terminals. Now use multimeter to check that the power is really off from water heater. Turn off the power breaker that powers your water heater. The reading on the multimeter should be zero.

You can also try a voltage stick instead of it is available. High limit reset button check. Use the screwdriver to set the lower thermostat to the highest setting. Turn the water heater power back on and use a multimeter to check that there is power coming to the water heater.

A thermostat with nc contacts should open eventually and the reading on the lcd should swing from 0 00 ohms to ol a thermostat with no contacts should eventually close and the lcd readout should swing from ol to 0 00 ohms. Now let us get started with the following steps on how to test a water heater with multimeter.