What to Do if your Water Heater is Not Heating: DIY Repair Tips

You turn on the shower, but there’s no hot water – just a barely warm stream. This is the last thing anyone wants when trying to get ready for work.

Why is your water heater not heating up? Is it dead? Is the problem serious enough to require a plumber? It’s a real inconvenience, and a cold shower always seems to happen at the worst possible time.

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The good news is that the list of possible culprits when your water heater is not heating up is short. With some troubleshooting knowledge, it should be relatively easy to identify the fault and fix the unit. You might even be able to repair your water heater without having to call a technician just yet. However, before you do anything, it’s essential to go through a few obvious things to see if you can fix the problem.

Are you ready? Let’s get started and figure out why your water heater is not heating up properly.

Important note: With anything electrical, make sure to turn off the power at the breaker before working on your gas or electric device.

Water Heater Is Not Heating: 7 Common Problems and a Troubleshooting Checklist

Either you are the owner of an electric or gas heating unit, below is the list of the common reasons why your water heater is not heating the water:

  1. Electrical supply disruption
  2. Low gas flow (pressure)
  3. Pilot light malfunction
  4. Reset button tripped
  5. Broken heating elements
  6. Faulty thermostat
  7. Bad ECO

Check Your Electrical Supply

If your water heater is not heating, the first thing you need to check is your power supply. Was there a power cut in the night that caused a breaker to pop? If so, that’s an easy fix.

Is the device switched on?

Perhaps someone in the house has switched it off and forgotten to put it back on.

Why anyone would do that is a complete mystery; however, you can deal with them later. The priority is to get hot water flowing again fast.

Do you have a timer fitted to your system?

If you do, has it been switched off or changed? Could it be a blown fuse or tripped breaker? You can easily change the fuse or reset the breaker, but if that doesn’t work and it blows again, call an electrician.

So, if the circuit breaker has tripped, and you want to reset it, simply flip it to OFF then to ON position.

Repair Your Low Gas Flow

If you have a gas-fired water heater, make sure that your gas supply is turned on and that you have a good gas flow and pressure. You can contact your local gas provider to check if there are any ongoing issues in your area. Low gas pressure can cause your heater to shut down. If you use propane, check if your tank is empty or low on propane gas.

Pilot Light Malfunction

Check if your pilot light is lit. If it’s burning, but there are no flames in the burner, it could be due to the reset button that has tripped. If the pilot is off, try relighting it using the correct procedure. If it doesn’t stay lit, then it could be a faulty thermocouple.

Thermocouples are designed to detect the pilot flame, and if the pilot goes out for any reason, the thermocouple will shut off the gas supply for safety. They are inexpensive and easy to replace.

Alternatively, your gas water heater may have an electronic ignition which is more energy-efficient than a constantly lit pilot light. These operate electronically only when heat is required. One type uses a small spark like a lighter to ignite the burners, and the other uses an electrically powered hot metal system like a lightbulb filament.

Unfortunately, these units won’t last as long as your heater, so they will fail at some point and usually require professional help to diagnose and replace.

Reset Button Tripped

To ensure that the reset button hasn’t tripped out, turn off the power supply and remove the cover panel to access the thermostat and the reset button, typically marked in red. Push the button back in and listen for a definitive click. Reattach the cover and turn the power back on. Wait for the water heater to start and run for a few minutes to confirm that it’s working properly.

It’s worth noting that the reset button may trip due to several reasons such as a power surge, a faulty heating element, a defective thermostat, or a triggered energy cut-off (ECO) switch. If the reset button trips again immediately after resetting it, you will need to locate and address the underlying issue by repairing or replacing the damaged component.

Heating Elements (Electric Water Heaters) Broken

If you notice that your water is cooler than usual, it’s possible that both of your heating elements have blown and need replacement. However, if the water is warm but not hot, it may be that only one heating element has failed. While it’s not common for both elements to fail simultaneously, it can happen. Typically, one will fail, followed by the other shortly afterward. It may be a good idea to replace both elements and keep the used but still-serviceable one as a backup spare. This can save you from the inconvenience of another outage in the future.

Thermostat Failure

A faulty thermostat is often the culprit when there is no hot water. Fortunately, they are relatively easy to replace and typically don’t require draining the tank. An electric water heater typically has two thermostats, one for the top element and the other for the lower one. It’s important to note that upper and lower thermostats are different, so be sure to purchase the correct ones by consulting the manufacturer’s handbook or checking their website.

In the case of a gas-fired water heater, the thermostat is integrated into the gas valve unit. If the thermostat malfunctions, you will need to replace the entire gas valve unit. This is also a job that doesn’t require emptying the tank but may be best left to a professional plumber in your area.https://www.youtube.com/embed/5f6UFwRlXr8

 Energy Cut Off Switch (ECO) Fails

In gas water heaters, the energy cut-off (ECO) switch is an important safety feature that monitors the temperature and shuts off the heater to prevent overheating and potential fire hazards. If the ECO switch fails, it can cause the heater to intermittently turn off or prevent it from turning on altogether.

Unfortunately, since the ECO switch is integrated into the gas valve, replacing the valve is usually necessary to fix the issue. It’s important to have a qualified professional handle any gas valve replacements to ensure proper installation and safety.


If you managed to locate the fault and get your water heater back up and running again – well done, it’s a great feeling, and you’ve saved yourself some money!

However, for serious issues involving electricity or gas, it’s best to call a professional.

But, at least by reading this short piece, you will now be able to talk knowledgeably about your water heater when the plumber arrives. Knowing how to describe the problem is crucial, as it will save you time and money.

While you may have a range of tools that you keep for odd jobs around your home, an excellent addition to your kit (if you don’t already own one) is a multi-meter or multi-tester. This inexpensive, handy piece of equipment can quickly identify whether a component is faulty or not, saving you time and money.

There are many excellent instructional videos online that can guide you through the basics and help you master these essential instruments.

Hopefully, you won’t need to use your troubleshooting skills very often, especially if you give your water heater some regular care and attention. The better you care for it, the longer it will serve you without any issues, and you can be confident in getting hot water every time you need it!

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