7 Steps To Test Electric Water Heater Thermostat (2021)

If you check the electric water heater Thermostat, there are two thermostats in the unit. One is at the top and the other is at the bottom. Each of these devices controls two different heating elements.

If you open the hot water tap and run out of cold water, the upper thermostat will be damaged. However, if the water gets hot and then cold, it will damage the floor thermostat.

However, you need to know how to test the water heater thermostat to find the device with the fault. You can resolve it by completing this task. Whether you’re using a propane water heater or another type, the thermostat is great for adjusting the temperature. But first, let’s see how the thermostat works.

How does the thermostat work?

Electric water heaters usually have three main features. This includes heating elements, thermostats, and switches to prevent the device from overheating.

You can use a thermostat to make hot water suitable for a variety of purposes. For example, the amount of heat required for washing may differ from the amount of heat required for showering. It also controls the current flowing through another thermostat or heating element.

Electric heaters with a storage tank of at least 30 gallons come with two heating elements, each with a thermostat. The upper thermostat acts as the primary thermostat, despite the upper limit switch. However, the lower one detects changes in water temperature.

Both thermostats (on the same boiler) do not have the same characteristics. They do not work at the same time.

The upper limit switch is in the upper limit position of the thermostat. There is also a button to disable it, especially if the water is above 170F. Press this button to return to the default settings.

To set the thermostat on the water heater, both thermostats must be set to the same temperature. Alternatively, you can set the upper element to a lower temperature and activate the lower element first.

For water heaters with smaller tanks (up to 30 gallons), a single thermostat and heating element provide temperature control. However, it uses an upper limit switch like a large water heater.thermostat work

How to test a water heater thermostat

If you want to test the thermostat with an electric water heater, you should also check the heating element. This is especially important because open and grounded heating elements lead to inaccurate testing.

You will need a screwdriver to check for mistakes. You also need to check the thermostat of the water heater using a digital multimeter tool. Next, to test a water heater with a multimeter, let’s start with the following steps:

  1. Go to the thermostat terminal and check if the power is on. In this case, the value of 240V is displayed on terminals 1 and 3. However, if you do not see the value, check the power supply. Also, check the current of the upper limit switch.
  2. Turn the knob to the minimum setting to deactivate the lower thermostat. Then raise the temperature of the upper thermostat to check for errors.
  3. Place the multimeter pole on terminal 1 and the blue heating element cable. This helps determine if there is the power between the upper heater element and the blue wire.
  4. If the device reads 240V, it means that the setup is powered. Next, place the pole on terminal 2 and the blue wire of the heating element. However, if there are no measurements, the thermostat is defective.
  5. Switch to the lower heating thermostat. Set the top thermostat knob to the minimum setting and the other thermostat to the maximum setting.
  6. Return to the red wire on terminal 1 and the lower heating element. Attach probes to both to detect power. If 240V is displayed, the configuration is powered.
  7. Place the probe on terminal 2 and the red wire on the lower heating element. If there is no reading, the thermostat should be replaced with a new one.

How to replace a Faulty thermostat in an electric water heater

Replacing the thermostat of an electric water heater is as easy as installing an electric switch. Once you know how to test the thermostat, you can even repair it without emptying the storage tank. However, you should turn off the power and check the cable tension before an accident occurs.

If the water is very hot, both thermostats on the stove need to be replaced. Even if the problem is caused by one thermostat, it is advisable to freely replace the two thermostats.

Before changing your current thermostat, it is advisable to buy a new thermostat of the same brand. If you can’t find such an item, look for a suitable replacement from another manufacturer.

Be sure to add the non-contact voltage tester and driver to the list.

Deactivate the Power Supply

Turn off the switch connected to the water heater and turn off the power. Water heater switches typically consist of two separate unipolar switches rated at 30 amps. However, some models offer more amps.

Remove the cover that protects the thermostat and heating element of the electric water heater. Some models come with a screw plate, so you may need to use a screwdriver. Be sure to remove the insulation on the back of the panel. However, do not touch the wires.

Make sure the thermostat is not working to prevent electric shock. At this point, you can use a non-contact voltage tester to check the threaded terminals and wires.Deactivate the Power Supply

Remove the defective thermostat

Take a picture of the thermostat connection. This photo will be used as a guide after learning how to test the thermostat. You can also draw as soon as you are ready.

Loosen both screw terminals on the thermostat. Then pry open both strands. Then loosen the thermostat from the retaining clip and remove it from the chamber. Use minimal force to prevent damage to the clips. Use minimal force to prevent damage to the clips.Remove the defective thermostat

Set up a new thermostat

Secure the new thermostat to the corresponding clip. Make sure it is properly placed on the surface of the storage tank. Connect both wires in the circuit to the appropriate threaded terminals. Tighten the screw to lock it in place.

Set the thermostat temperature to your preferred setting. You will need a flat-blade screwdriver here. It is recommended to set the temperature to 120 ° F.Set up a new thermostat

Add a finishing touch

Replace the chamber plate and thermostat insulation. Activate the circuit breaker and reconnect the circuit to power. Turn on the water heater for 2 hours, then turn on the hot water tap to see if the water is sufficiently heated.

How to Troubleshoot a Defective Thermostat on an electric water heater

Troubleshooting a water heater thermostat may seem difficult. However, you can use this guide to manage this business without contacting an expert.

  • Go to the switch and turn off the thermostat. This procedure is important to protect against electric shock. If you are using bipolar switches, both switches will be off at the same time.
  • Pull out the two covers that protect the thermostat. Under the cover, there is insulation corresponding to the opening. Remove it and save it for future installations.
  • Find the thermostat and heating element plastic plate. The button is at the bottom of the control panel. Press it to verify that it is working properly.
  • When you press the button, check the movement of “snap”. If you feel it, turn on the device and let it run for a few minutes.
  • Make sure the drive is not turned on, especially if you want to continue working on the drive. To do this, shake the non-contact voltage tester near some of the wires above. If you do not hear any lights or beeps on the meter, the thermostat has no power.
  • If the tester does not find the reading, it still acts as if the device is powered. Carefully remove or loosen the plastic cover from the thermostat. To prevent accidents, do not put your finger deep inside the device.
  • Take out the voltmeter and set it to a minimum of 240 volts. Place the tip on all the screws on the top. If there is a reading, the device is turned on. Please turn it off and check again. Do not power the device.Troubleshoot a Defective Thermostat on an electric water heater

Wrap Up

The electric water heater is equipped with a thermostat like a water heater. Fortunately, testing and repairing a failed thermostat requires tools such as a multimeter and a few screwdrivers. You don’t even need any special skills to solve this problem. All you have to do is follow these simple steps.

  • Turn off the power
  • Test the drive.
  • If you encounter any problems, remove the current thermostat and install a new one. It is advisable to check for the presence of electricity in the device to prevent electric shock while working.

We hope you enjoyed this article Test Water Heater Thermostat. If you have any comments, please enter them in the fields below.

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