Common Reasons Why the Water Heater Keeps Turning Off

It’s hard to name something worse than being in the middle of a perfect-temperature shower when the tap suddenly turns ice cold. Besides being cold and frustrated, now you have to figure out how to fix the problem at hand so it doesn’t happen again. 

If your water heater keeps turning off, this article is for you. Keep reading to learn why your gas or electric water heater may be malfunctioning and what you can do about it. 

Reasons Your Gas Water Heater Keeps Turning Off

If your gas water heater keeps turning off, it may be a sign of a malfunction—or your system may have simply outlived its lifetime. The answer to how long a water heater lasts depends on how often it’s used and maintained, but in general, the answer is about 10 years. So, if it’s been more than a decade since you’ve replaced your water heater, you may be out of luck. 

But if it’s a relatively new gas water heater, a few things may be causing your issues, like a malfunctioning thermocouple or a clogged inlet.

1. Gas Supply Issues

If there’s a problem with the gas supply, your water heater can’t do its job. Something like a blockage in the gas line or a faulty gas valve can disrupt the flow of gas and cause your water heater to keep turning off. 

If you suspect a gas issue, turn off your gas and contact a water heater repair contractor immediately. 

2. Malfunctioning Thermocouple 

A thermocouple is what connects the gas control valve to the outside of the water heater. It helps convert the heat from the pilot flame to an electrical current that turns on the heat by controlling the flow of gas. 

If a thermocouple is bad, there will be no gas to the pilot or the burner—meaning no heat. A good way to figure out if it’s the thermocouple is to see if the pilot light is on. If it isn’t or won’t stay lit, the thermocouple could be the issue.

3. Dirty Pilot Tube

Your pilot tube can get clogged if it’s too dirty, preventing the pilot light from getting enough gas to stay lit. You can try cleaning it yourself by following these easy steps:

1. Turn off the gas and power to your water heater

2. Vacuum out the pilot tube

3. Use a brush to clean up any additional residue

4. Wipe the pilot burner with a soft brush

5. Secure back in place

4. Clogged Air Inlet

Air intake vents can easily become clogged with debris, pests, or even stray items (like clothing if it’s located near your laundry). Without a good incoming air supply, your water heater will not function properly and may keep shutting off. 

Just like the dirty pilot tube, vacuum and brush out the air intake vent to ensure adequate airflow. Your water heater should also be located in a well-ventilated room with access to oxygen—that is, no closed doors without a vent.

5. Faulty Main Control Valve

The main control valve lets you control the temperature of your water heater and turn it off and on. When it’s not working properly, your water heater can keep turning off or be inoperable. If it is a faulty valve, contact a pro for help. 

6. Clogged or Damaged Flex Tube

The flex tube runs hot and cold water into your system. If clogged or damaged, it’s easy to see why your hot water heater isn’t working how it should. The easiest way to clean a flex tube is to flush your water heater. 

Here’s how to drain a water heater: 

• Turn off the power and gas

• Let the water cool down, unless it’s not hot

• Release pressure in your water line by running water elsewhere, like your upstairs sink

• Attach a garden hose to your drain valve and place a bucket under the other end of the hose

• Open the drain valve

• Once empty, run more water through your system

• Close the valve, turn the power and gas back on

Reasons Your Electric Water Heater Keeps Turning Off

Photo: sturti / E+ / Getty Images

While gas is commonly known to be dangerous, some homeowners may be able to try their hand at small wiring repairs. 

But if you’ve never attempted any sort of electric work before, just like with gas water heaters, you should leave the work to a professional. One wrong move could lead to electrocution, fire, or damage to your entire electrical system. 

1. Circuit Breaker

If your water heater keeps tripping your breaker, your wiring may be faulty. 

To test if it’s your breaker, try turning it back on once it’s off. If it immediately turns back off without any sort of action, it’s probably the breaker itself.

2. Issues with the Thermostat

When a thermostat breaks, it’s no surprise that your water temperature isn’t right. In some cases, it can cause your water heater to turn off completely. 

For example, if your system can only handle up to 175 degrees, but if the faulty thermometer allows it to reach 185, the system could be shut off automatically.

3. Built-up Sediment

Water contains natural sediment, which can build up inside your heater over time. If there is too much sediment, your tubes and valves can become blocked, disrupting your water flow. 

If you haven’t in a while, try draining your water heater to see if that helps your water heater get back on track. Look up draining tips for your specific model, but in general, you can follow these steps:

• Turn off the power

• Let the water cool down, unless it’s not hot

• Release pressure in your water line by running water elsewhere, like your upstairs sink

• Attach a garden hose to your drain valve and place a bucket under the other end of the hose

• Open the drain valve

• Once empty, run more water through your system

• Close the valve and turn the power back on

4. Faulty Wiring

If it’s none of the above, there could be faulty wiring. In some cases, you may be able to see some issues, like a loose wire. But if there’s nothing noticeable or out of place, the bad wiring could be hidden in your system itself. 

Either way, reach out to a pro for help.

Tips That Can Help Prevent Your Water Heater from Turning Off

Photo: Ruslan Ivantsov / Adobe Stock

While you may not be able to fix the water heater on your own, you can help prevent issues in the first place by:

• Maintain it regularly: Give your water heater a once-over at least once per year. Test the valves, check the anode rod, and look for any visible issues. Catching them before the problem gets serious can save you a lot of time and money.

• Get a professional inspection: You can also outsource your maintenance to a professional who can look for any issues and make sure all your settings are correct. Plumbers cost as low as $45 per hour, but that hour of work could save you hundreds in repairs.

• Flush it once a year: Over time, sediment and other debris build up in your water tank, leading to decreased efficiency. Draining your water heater once a year can keep your system running at its highest (and hottest) potential.

• Insulate your tank and pipes: By insulating your tank and pipes, you can reduce your utility bills and ensure your system doesn’t have to work too hard to keep up with demands.

• Turn it down a few degrees: The standard settings allow for pretty hot water, but most homeowners won’t ever use water at its highest heat. You can turn your settings down a few degrees on the control valve to give your heater a bit of a reprieve.

Fixing Your Water Heater vs. Replacing Your Water Heater

While the upfront cost for a new water heater can be intimidating, sometimes a full replacement might turn out to be the wiser and more economical choice in the long run.

If your water heater is an older model, replacing it with a newer one can lower your energy bills since newer models tend to be more energy-efficient. Also, a water heater nearing the end of its lifespan is not always worth fixing as it may completely break down sometime soon, rendering the money you spent on repairing a complete waste.  Finally, upgrading your water heater also increases your home value if you plan to sell in the near future.

However, if your water heater is relatively new, you should absolutely try to fix it. Contact a licensed and insured water heater contractor and ask for an inspection. Based on what is wrong and the quote, you will have a better idea of whether to repair or replace your water heater. 

DIY Fixing Your Water Heater vs. Hiring a Pro

In most cases, trying to DIY a water heater repair isn’t worth the time or effort. You could actually end up causing more damage to your heater or home, and in some cases, DIY repairs will void your system’s warranty. Your best bet is to call a local water heater pro to get the job done for you. 

Most plumbers charge per hour for their services, so the price will depend on the complexity of the job. Homeowners spend anywhere from $91 to $1,700 on average for a repair—with the average water heater repair cost landing right at $600. 

If you have to replace the system completely, expect to spend upward of $1,800. But, this cost can vary based on where the heater is located, whether you have a tank or tankless water heater (tankless water heaters cost much more than tank ones), and whether your project requires any plumbing upgrades. 

Questions to ask a Water Heater Pro

Below is a list of questions to ask your water heater pro while you are on the phone:

• How long have you been in business? Can you provide past client testimonials?

• Have you worked on this brand/model of water heater before?

• Are you licensed and insured?

• Do you provide any warranties after the job is done?

• Do you charge an upfront fee to come out for an inspection?

• What do you think is wrong with my water heater based on what I just described?

If the answers sound convincing, you can move forward and schedule a time for the pro to come inspect your water heater on-site. Once they get there, here are a few additional questions to ask:

• How much will the repair cost me?

• Do you have any financing options?

• How long will the job take?

• When is your earliest availability, and can you work with my schedule?

• Do you think it’s better to just replace the water heater?

• Can you help me find the best deal for a new water heater?

Taylor Sansano contributed to this piece.