Why My Water Heater No Longer Turns On?

Aug 03, 2023, 12:35pm

A water heater provides a home with hot water. Some failures may occur on these devices. When the water heater does not turn on, it will be necessary to check:

  • the power outlet
  • the voltage on the water heater
  • the thermostat
  • tank
  • resistance

Water heaters are critical appliances that ensure we have access to hot water for showers, dishwashing, laundry, and more. So when a water heater refuses to turn on, it can disrupt many aspects of our daily routine. In this article, we will discuss the most common reasons why your water heater might not turn on.

Why My Water Heater No Longer Turns On?

1. Power Supply Issues

If you have an electric water heater, it may not be receiving power due to a tripped circuit breaker or a blown fuse. Checking your home’s electrical panel can help you determine if this is the problem. Ensure the circuit breaker for your water heater is not in the ‘off’ position. If it is, flip it back on and try again. If the fuse has blown, it will need to be replaced.

2. Pilot Light Out

For gas water heaters, a common reason why the heater might not turn on is if the pilot light has gone out. The pilot light is a small flame that ignites the gas burner in your water heater. If the pilot light has gone out, the water heater won’t receive the heat it needs to heat the water. Following the instructions in your water heater manual, you should be able to safely relight the pilot light.

3. Faulty Thermostat

The thermostat on your water heater controls the temperature of the water in your tank. If it malfunctions, it can prevent your heater from turning on. If the thermostat is faulty, it may need to be replaced.

4. Gas Supply Issue

If you have a gas water heater and the gas supply is interrupted, the water heater will not function. The interruption could be due to an issue with your utility company or a problem with the gas line leading to your water heater.

5. Failed Heating Elements

Over time, the heating elements in your water heater can fail or burn out. This failure is common in electric water heaters. If the heating elements are not working, the water heater won’t turn on. You’ll need to replace these elements to get your water heater working again.

6. High-Temperature Cutoff Switch Tripped

Water heaters come with a high-temperature cutoff switch as a safety feature. If the water in your heater gets too hot, this switch will trip, causing the heater to shut off. If the water temperature has returned to a safe level and the switch has not reset, it might prevent your heater from turning on.

Why My Water Heater No Longer Turns On?


If your water heater is not working, descaling may solve the temperature problem. To check this, you will have to disassemble the device.

  • Turn off the water supply.
  • Place a basin under the tank and activate the valve located on the safety block of the water heater. This will open the safety shut-off valve and allow water to drain through the siphon.
  • Once the water in the tank is empty, remove the cap from the water heater.
  • Turn off and remove the thermostat.
  • Disconnect the sensor cable connected to the electronics, then remove the sensor.
  • Place a basin under the tartar reservoir.
  • Remove the flange if you have weld resistance, then remove the block to clear the scale.


When your water heater doesn’t turn on, it can be a significant disruption. While some of these problems can be fixed by homeowners, others require professional assistance. If you’ve checked the most common issues and your water heater still isn’t working, consider hiring a professional plumber or a water heater repair specialist to examine your system and determine the cause.