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How To Bypass Thermal Switch On a Water Heater

How To Bypass Thermal Switch On A Water Heater

For many homeowners, having water heaters is a faster and more convenient way of having hot water around the house. However, the heating units are not cheap, and having trouble with the thermal switch can be frustrating.

One way to troubleshoot your water heater is bypassing the thermal switch if you have cold water during the winter. Though replacing a broken switch is the best idea, bypassing it can offer a temporary solution as you wait for repairs.

So, are you looking for a way to bypass the thermal switch in your heating unit? This post will give a comprehensive guide on how to get your water heater working again in case of a faulty thermal switch.


If you have a faulty thermal switch, bypassing the switch can help keep hot water running in the house.

The first way to bypass the switch is by removing the wires attached to it and then connecting them using a cable terminal. Disconnecting the wires to the switch allows current to flow directly to the heating element.

Additionally, you can also use a bypass kit for the job. The bypass kit is attached to the thermal switch, enabling current to flow through the circuit without going through the switch.

Regular maintenance is the best way to ensure your water heater works optimally and efficiently. If you are having trouble with the unit, let a qualified technician look at it.

What Is a Thermal Switch in a Water Heater?

What Is A Thermal Switch In A Water Heater

There are several ways that water heaters warm water before sending it through the pumping and into the sink or shower.

However, water can get hot without proper heat regulation and management, leading to serious accidents for you and your family. That is where the thermal switch comes in.

A thermal switch is one of the multiple safety devices installed in the water heater. The switch is made from a thermally sensitive material.

When the water in the tank heats beyond the material’s temperature threshold, it bends and opens the electrical circuit, stopping the current flow to the system.

By opening the circuit, the water in the reservoir starts losing heat, cooling down until the water temperature falls below the switch’s boundary.

Once that happens, the switch closes again, allowing electricity to flow and water to get heated.

Importance of Thermal Switch in a Water Heater

Importance Of Thermal Switch In A Water Heater

As we stated before, thermal switches are essential components of your water heater.

Before bypassing the switch, here are a few things you need to consider:

  1. First, prevent overheating: Too much heat in the water tank can cause it to overheat and explode without a thermal switch. This can cause serious injury to you and damage your property.
  2. Prevents scalding: If the water becomes too hot, it can cause burns and other serious injuries. The thermal switch regulates water temperature, ensuring it is within a safe range for you to use.
  3. Extends water heater’s lifespan: Likewise, overheating can also cause damage to the tank and other components of your unit. The thermal expansion increases wear and tear, leading to expensive repairs. By preventing overheating, the switch enhances the lifespan of your heater.
  4. Energy efficiency: The switch also enhances your appliance’s energy efficiency. The water heater needs to work harder to maintain the high-water temperature. This leads to longer heating cycles that consume a lot of energy.

Reasons for Bypassing the Thermal Switch in Your Water Heater

Reasons For Bypassing The Thermal Switch In Your Water Heater

Is it safe to bypass the thermal switch on your water heater? After looking at the benefits of having a thermal switch in your water heater, we recommend not bypassing it unless it is completely necessary.

Not only can bypassing the switch lead to serious injury, but it also increases the risk of potential explosions and fires in case of malfunctioning or overheating.

However, here are two scenarios when you should safely bypass the heater’s thermal switch:

  1. If you have a faulty thermal switch: In case of a malfunctioning switch that keeps tripping even when the water is within a safe temperature range, bypassing the switch is one option to get hot water back into the house. However, it would be best if you got the switch replaced as soon as possible.
  2. During high demand for hot water: Additionally, if the demand for hot water is high, especially when guests visit for the weekend, you might need to bypass the switch. This should provide hotter water for longer periods.
Insurance Cover

It is also important to note that your insurance might not cover accidents or damage after bypassing the thermal switch.

2 Ways To Bypass the Water Heater’s Thermal Switch

Bypassing your heater’s thermal switch is not advisable. In addition to being a fire hazard, there is also a possibility of electrocution. Therefore, you should always let a qualified technician work on it to be safe.

Always Check the Water Temperature

After performing a thermal switch bypass, you should always check the water temperature before use. This might prevent accidentally burning yourself.

There are two ways that the expert you called can bypass the thermal switch. They include:

1. Disconnect the Wire to the Switch

Disconnect The Wire To The Switch

The first method is disconnecting the wire that feeds power to the switch.

Follow this safety procedure when bypassing the switch:

  • Turn off the power supply to the water heater. If you own an electrical device, you can turn it off using the circuit breaker. However, if you have a gas heater, you must turn off the gas supply and pilot light.
  • Afterwards, you need to locate the heater’s thermal switch. The switch is usually found at the bottom of the unit near the heating element or the thermostat.
  • You need to disconnect the wires connected to the switch.
  • Find a cable terminal and use it to connect the two wires.
  • Turn on the heater’s power supply.

2. Install a Bypass Kit

Install A Bypass Kit

Another way to bypass the safety switch is using a bypass kit. However, the type of kit you use depends on the specific type of water heater model.

To use a bypass kit, follow these simple steps:

  • Turn off the appliance’s power supply using the circuit breaker or the gas supply.
  • Locate the thermal switch.
  • Remove the wires connected to the switch.
  • Install the bypass kit by connecting the kit’s wires to the thermal switch terminals.
  • Secure the wiring connection.
  • Afterward, connect the wires previously connected to the thermal switch to the bypass kit. Ensure all the wires match the correct terminal.
  • Turn on the power supply to the water heater.


Bypassing the water heater’s thermal switch is a good and fast fix if the switch malfunctions. However, without proper care, a thermal switch bypass can cause considerable harm to you and your property.

You should always let a qualified professional handle the project to prevent any electrical issues or damage to your water heater.

There are two ways to bypass the thermal switch in your water heater. First, the technician can remove the wires on the switch and connect them using a cable terminal, allowing current to flow directly through the circuit and keep the water hot.

Likewise, they can use a bypass kit, allowing the heating element to continue receiving power regardless of the water temperature in the tank.

It is important to note that bypassing the thermal switch is dangerous and should only be used temporarily for troubleshooting.

If your switch is faulty, you should have a technician replace it and check for other signs of damage to your heater.

Lastly, regular maintenance ensures your unit works optimally, reducing expensive repairs and utility bills.

Frequently Asked Questions

How Do I Fix a Thermal Switch in My Water Heater?

A faulty thermal switch can be a huge inconvenience when you want hot water during winter. However, replacing the switch might be demanding, so it is better to let a technician handle it.

Here are some safe steps to follow during the repairs:

  • First, turn off the water heater’s power supply. You should switch off the circuit breaker for an electrical heater. While for gas heaters, switch off the gas supply.
  • Afterward, you need to find the thermal switch. In most devices, the switch is near the heating element or the thermostat.
  • Remove the wires connected to the thermal switch.
  • Using a screwdriver, gently remove the switch from the unit.
  • Install the new thermal switch by matching it to the corresponding terminals.
  • Secure the thermal switch tightly to the heater.
  • Connect the wires you previously removed.
  • Turn on the power supply and test the new switch.

Is It Safe To Bypass the Thermal Switch On a Water Heater?

We do not recommend bypassing the thermal switch in your heater. Bypassing the switch can prevent the unit from cutting off current to the heating element, causing overheating and pressure to build up in the tank.

This may lead to scalding hot water running in the pipes or a fire hazard caused by the tank exploding.

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