Are Water Heater Thermostats Universal

After a while, your water heater thermostat might start to malfunction, and you’ll have to replace it. So, are all water heater thermostats universal? Can you fit any brand of thermostats with your current hot water system?

Most  water heater thermostats aren’t interchangeable or universal as there are several differences between the thermostats used in single-element water heaters and dual-element water heaters. 

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If you’re shopping for a new water heater thermostat, there are several factors to consider; the number of elements in the water heater and the voltage. 

However, there are multiple options to consider when it’s time to replace the thermostat. 

Different brands are designed to be used on various water heaters with no issues, as long as the thermostat complies with the voltage and number of elements of the water heater. 

Different Types of Water Heater Thermostats

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There are two different types of water heater thermostats. Dual-element thermostats are designed to work on dual-element water heaters. 

These heaters have two thermostats to control the hot water supply in your household. A single-element thermostat works if you have a single-element hot water tank. 

If you’re shopping for a new thermostat, you need to make sure that it’s compatible with your water heater. 

A single-element thermostat resembles an upper dual-element thermostat, but it has a different number of wire terminals, so these two aren’t interchangeable. 

At the same time, you can’t use a thermostat designed for a dual-element water heater in a single-element water heater. 

How Do You Know that Your Water Heater Thermostat Is Faulty

Single and dual-element heater elements work in different ways. A single-element water heater heats the water in the tank from the bottom up, while a dual-element water heater has two heating elements. 

Therefore, it’s able to heat the water in two different directions at the same time. As a result, it heats water faster and is more energy-efficient. 

If you’re using a dual water heater, one of the elements will always be on, as most manufacturers recommend adjusting the setting of the lower thermostat while leaving the upper one at factory settings. 

When the water heater is switched on, the upper thermostat will heat up almost 1/3 of the water tank and then shuts down and diverts the electric power to the lower thermostat to heat the rest of the water. 

Since these thermostats work differently, you need to identify which ones need to be replaced.

Defective Upper Thermostat

When your upper thermostat fails, the water heater won’t work. The upper thermostat controls the lower one and should heat a portion of the water before it shuts down, so the other lower thermostat can start working. 

When you have a defective upper thermostat, the lower one will never work. 

Defective Lower Thermostat

You can tell that your lower thermostat isn’t functioning when the water never reaches the desired temperature

Despite changing the temperature to high, your water will always be lukewarm. You might also have hot water, but you’ll run quickly out of it. 

This is because the upper thermostat stops working when 1/3 of the tank has reached the desired temperature. 

At this point, the lower thermostat should start working and heat the rest of the water. 

However, when the lower thermostat is defective, this process won’t start because the thermostat won’t turn the heating element on. The rest of the water will be cold. 

Checking Your Water Heater Thermostat

You can check that your water heater thermostat is faulty by running a few tests. Before you start, turn off the power and remove the access cover to the thermostat. 

Here is a list of the tools you’ll need.

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  1. Check that there’s no access to electricity by connecting one probe of a multimeter to the unpainted metal housing and the other to one terminal of the thermostat. If it reads (zero), you can start checking the thermostat. 
  2. Remove the wires from the thermostat and use the multimeter to test the terminal for continuity. Connect the probes to both terminals and check if it reads close to zero. If it doesn’t, then your thermostat is faulty. 
  3. Touch one lead to the common terminal and the other to the heating element terminal. If the water is below the thermostat setting, it should read close to zero. 

In most cases, it’s recommended to replace both the thermostat and heating element. All these components are related to one another, so if one of them fails, the others will soon become faulty. 

You need to hire a professional to replace the water heater thermostats. Professional handymen have access to the required tools and will ensure that the new thermostats are compatible with your water heater. 


So, are water heater thermostats universal?

There are two types of water heaters, single and dual-element heaters. Both types have thermostats that control the temperature and supply of hot water. 

All thermostats work in the same way, but they’re not universal or interchangeable. So you need to make sure that the thermostat you’ve picked is compatible with your water heater, and the best way to do that is to hire a professional to have it examined and replaced.

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