Why Does My Hot Water Heater Keep Turning Off?

There are times when your water heater will simply shut off. Trying to determine why your hot water heater keeps turning off will involve a little troubleshooting, but don't worry, you should be able to figure it out.

This article will help you determine what's causing your gas or electric water heater to shut down, and point you in the direction to solve the problem.

Why a Gas Water Heater Keeps Turning Off

If you have a gas water heater there are a few reasons it may be turning off. A few of the causes are easy fixes, and others you may want to hire a professional to do the repair. Either way, the fix should be less expensive than purchasing a new water heater!

Gas Supply

Although the gas supply isn't typically the reason your gas water heater is shutting off, it is a good place to start. If your water heater isn't receiving gas, it will most definitely not be able to heat water.

On the lower part of your water heater you'll see a gas line which connects to the main gas control valve. Often , but not always, the line is a yellow flexible line. Follow it back and you'll eventually find a metal pipe with a gas shut-off valve.

The gas shut-off is usually a ball valve and its a code requirement that'll allow you to stop the flow of gas to the water heater.

It's possible that the valve was inadvertently turned off, or accidentally bumped leaving it partially off. Simply check that the valve is fully open.

Any damage or repairs that need to be done to the gas supply should always be done by a professional.

Thermocouple

A faulty thermocouple is the most common reason a gas water heater will continually shut down.

The thermocouple allows gas to flow to the burner when it detects that the pilot light is lit. When the thermocouple isn't working properly, it will shut down the gas to both the pilot and burner in order to prevent gas leaks.

Here are two common issues that could cause your thermocouple to malfunction:

Dirty Thermocouple

If the thermocouple is covered in a layer of dirt and/or grime it may not be able to sense the pilot flame.

Since the thermocouple can't detect the flame, it'll shut down the gas supply to the water heater. 

Damaged Thermocouple

When a thermocouple is bent or damaged it won't be able to do its job. Although, it may have been damaged by being handled, it's not uncommon for them to simply become damaged as they age. 

If your thermocouple is bent, you can try to gently bend it closer to the pilot light. However, if it's broken or damaged you'll need to replace it with a new one.

> > Read More About Thermocouples HERE < <

Pilot Tube

Another common problem that can cause a gas water heater to shut down is a dirty pilot tube.

The pilot tube is responsible for delivering gas to the pilot light. If the tube is clogged, or even partially blocked, the pilot light flame will go out.

You should be able to clean and unclog the pilot tube with slender brush or object such as a nail. Be gentle and patient. If your pilot tube is extremely dirty, it may take a few cleanings to get it working again.

Flex Tube

A less common problem could be with the flex tube. This is a long tube which connects the burner to the gas controller. If the flex tube is clogged or damaged it won't be able to supply gas to the burner.

Check for kinks in the flex tube and gently straighten them. If you notice visible damage there may be a gas leak.

Main Control Valve

If the thermocouple, flex tube and pilot tube look to be in good working order, then check the main control valve. Although, it's rare, the main control valve can fail.

The main control valve regulates the water heater's gas and water pressure. It begins by supplying a small amount of gas to the pilot light, and then fully opens the main valve so the gas supply is steady.

If the main control valve isn't properly working it'll close the gas valve, stopping the flow of gas.

When the main control valve is faulty you may notice the following:

• Extremely hot water (above the set temperature)
• Pilot button won't pop back out after pressing
• Control knob is faulty

There's not much you can do if your main control valve is faulty other than replace it. They are generally relatively expensive and should be replaced by a professional plumber.

> > Read More About Gas Control Valves HERE < <

Air Inlet

Newer gas water heaters position the air inlet screens at the bottom of the appliance. These screens can easily become clogged with dirt and debris and not allow enough air to the gas burners, which results in your water heater shutting off. 

Check your air inlet for clogs or blockages. Depending upon it's location, you can use a wire brush or compressed air to remove any dirt or debris.

Why an Electric Water Heater Keeps Turning Off

Electric water heaters have a variety of electrical components that all work together to deliver hot water. When one of these components fails, the water heater will abruptly shut down to prevent an unsafe situation.

Thermostat

Electric water heaters use a thermostat to regulate the temperature of the hot water within the tank. The thermostat switches on and off to keep the water at the set temperature.

However, if the thermostat malfunctions, and fails to turn off when the set temperature has been reached, it will automatically shut down the power to the water heater when the water temperature reaches 180°F. It could even trip the breaker in your electrical panel.

The problem could also be related to loose wiring or corrosion, but either way, there's a problem, and you'll need to take action sooner rather than later.

Thermostats can be reset, however, if this happens several times, there's likely something wrong and you should contact a professional to troubleshoot the issue.  

> > Read More About Thermostats HERE < <

Heating Element

The heating element is controlled by the thermostat and can become damaged and stop working altogether. If the heating element's casing cracks it could develop a short circuit.

In some cases, the high-limit switch on the thermostat may trigger, which will shut down the flow of electricity to the water heater.

Water heater elements can be replaced and are relatively inexpensive. You can do it yourself if you enjoy DIY projects, or hire a professional to do it for you. 

> > Read More About Heating Elements HERE < <

Electric Wiring

On the top of your electric water heater is a junction box which connects the appliance to your home's electrical panel.

If your water heater was not properly wired when it was installed, it could cause the breaker to "pop" and shut the water heater down.

The problem could also be related to the wiring that runs between the water heater and the breaker panel.

It could even be the breaker itself. Breakers wear out and need to be replaced over time. Or possibly, the water heater's breaker is not the right size.

Whatever the reason, if you're having an electrical issue with your water heater you should shut off your water heater and call a professional to troubleshoot the problem.