how-to-test-water-heater-thermostat

How to Test Water Heater Thermostat – DIY

Now that you have installed a water heater, it’s time to understand some of its components, so that you won’t face any difficulty in order to maintain it.

There is no doubt that water heaters are machines and the machine needs adjustments some times. And the adjustment cost of water heater is quite high that you must be wanted to keep the distance from it.

Don’t worry, we are here to explain to you one of the most important components of the water heater that is none other than the thermostat.

Yes, the thermostat.
You will find two thermostats in your water heater. One is at the top and the other is at the bottom. Both of them control their respective heating elements. The upper thermostat must be damaged if your water heater is giving cold water after turning on the hot water tap and if the outlet water is getting cold after some time then the lower thermostat is damaged.

Now instead of calling a professional, you can adjust it on your own. For this, all you need is to detect the faulty unit of your thermostat and fix it. But before that, you need to know how the thermostat actually works.

Working of a Thermostat

In general, there are three main components in an electric water heater. One is the heating element, second is the power switch to avoid overheating problem and the last one is the thermostat.

Mainly, the thermostat is used to adjust the temperature of water for different purposes.
For example, the temperature of water required for doing dishes can differ from the temperature of water required for taking a bath. Other than this, the thermostat controls the current flowing from one thermostat to another thermostat or from the thermostat to the heater.

The upper thermostat is the primary one that contains the high limit switch and the lower thermostat is used to detect the change in the temperature of the water.
It’s not necessary that both thermostats will do the same work, their work can vary according to the water heater unit.

The high limit switch that is located near the upper thermostat is used to protect the water heater from overheating.

It will stop working if the temperature of the water goes above 170 F. You can also reset your settings using this button.

In order to set the temperature of outlet water, you need to set both thermostats on similar temperatures.

Testing of Thermostat

how to test water heater thermostat
Check the power supply of the thermostat. If you get the reading of 240V on terminal 1 and terminal 3 then the power is on but if you get no readings then the power is off. In this case, also check the current at the high limit switch.
To look at the faults in the upper thermostat, you need to turn off the lower one. In order to turn off the lower thermostat rotate its dial to the least.
Touch the terminal 1 and blue wire of the heating element with the prongs of
multi-meter. With this, you can check whether the power is supplied to the upper heating element and the blue wire.
If it shows the reading of 240V then it means power is supplied and now you can move the prongs to the terminal 2 and the blue wire. But if there are no readings then the thermostat is faulty.
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.
Place the prongs of the multi-meter on the terminal 1 and red wire of the lower heating element. If the reading shows the value of 240V then the power is on.
Now you need to move the prong on the terminal 2 and red wire. If no reading is shown then your thermostat is faulty and you need to replace it.

Replacing the Faulty Thermostat on an Electric Water Heater

Now that you have detected the faulty thermostat, its time to replace it. Replacing the thermostat of an electric water heater isn’t rocket science, in fact, it’s very easy.

But one thing you should always keep in mind that, switch off the power supply before starting replacement to avoid adverse circumstances. If you want the extra hot water then you are advised to change both thermostats even if only one is damaged.

It’s better if you find the new thermostat of the same brand but if you are not able to do so then you can also look for the suitable one from different manufacturers.

Now that you have learned about all the prerequisites of replacing the thermostat, you are ready to replace it on your own. All you need is to follow the instructions mentioned in the following steps:

STEP 1: Turn off the power supply for safety purposes. Take out the panel, some models may have screwed panel so you may need a screwdriver to take it out.

STEP 2: Now you need to pull out the defective thermostat. For this, unscrew the terminals on the thermostat

STEP 3: Now set the new thermostat at the same place using a screwdriver. Make sure to place it correctly on the storage tank. Attach the circuit wires to their respective terminals and then tighten the screws.

STEP 4 : After that, you can set the thermostat according to your desired temperature bu using a flat blade screwdriver.

STEP 5 : Now finally, replace the chamber and the insulation of thermostat, turn on the power supply, and enjoy the hot water without any problem.

Conclusion

It’s very easy to test and replace the faulty thermostat of your water heater. All you need is some tools (screwdriver and multi-meter etc. )and basic knowledge of the replacement. You don’t need professional skills for this. You just have to be a little careful to avoid any kind of accident. In a nutshell, all you need is to:

  1. Turn off the power supply.
  2. Test the defective thermostat, using a multimeter.
  3. If it is defective then pull it out and replace it with the new one.

Conclusion

So how to test water heater thermostat?

It’s very easy to test and replace the faulty thermostat of your water heater. All you need is some tools (screwdriver and multi-meter etc. ) and basic knowledge of the replacement. You don’t need professional skills for this. You just have to be a little careful to avoid any kind of accident. In a nutshell, all you need is to:

1. Turn off the power supply.

2. Test the defective thermostat, using a multimeter.

3. If it is defective then pull it out and replace it with the new one.


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