Water Heater High Temperature Shutdown [Reasons + Solutions]

You wake up in the morning and find there is no hot water. So, you go to your water heater and try to ignite it. But the heck is- you fail to turn the heater on or keep it stay on.

What you notice is- when you set the knob to pilot, you notice the status light shows you 4 flashes. And it indicates the water heater high temperature shutdown issue. 

water heater high temperature shutdown

Several reasons will lead the water heater to this lockout mode. A faulty gas valve, a bad thermocouple, and a defective thermostat are some of them. 

Fortunately, we compiled this troubleshooting guide to let you know how to fix high-temperature shutdown. So, stick with us till the end of this guide. 

Water Heater High Temperature Shutdown [5 Reasons To Fix]

From the below section, you can learn what causes high temp shutdown on water heaters and how to fix those issues. 

water heater temperature problem

1. A Bad Thermostat

Your water heater may feel too hot suddenly due to a defective thermostat. This piece of water heater equipment will control the on-and-off cycle of the heater elements. In other words, the thermostat allows you to adjust the temperature. 

water heater bad thermostat

If the thermostat doesn’t work properly, the heating element will continue to heat the water. It may lead the water temperature to an unsafe level, and your heater may activate the ‘high-temperature shutdown’ mode. 

How To Fix:

Replacing the faulty thermostat will be an easy fix for this issue. If you are not mechanically inclined, you can hire a professional to change the thermostat for you. You can also check the below tutorial to learn how to replace the water heater thermostat. 

2. Pressure Relief Valve May Get Clogged

The steam that builds up inside your water heater may make the water heater hotter than normal. That’s why a pressure relief valve comes into play to let the steam escape from the heater.

pressure relief valve get clogged

If the valve gets clogged by dirt, it doesn’t function properly. Consequently, your water heater may get overheated which may set it to high-temperature shutdown mode. 

How To Fix:

If the pressure relief valve gets blocked, we recommend you shut off your water heater immediately. Then, call a certified plumber to fix this issue for you. 

3. Defective Wire Connection

Loose wire connections on the circuit board may be the culprit behind this issue. Maybe unplugging the wires and reconnecting them again will solve the problem. Below, we break down how to detach and reconnect the wire. 

loose wire connection on the circuit board

How To Fix:

You need to reset the electronics to fix the issue. To do this, pull out the wire that goes to the ignitor. Then, you should remove the connector that goes down to the two terminal temp sensors. Next, unscrew the screw that holds the cover on it. Afterward, pull the cover by removing the two plastic holders. 

And then, detach the two-wire connectors from the circuit board. Count from 1-20 and then reconnect the wire connectors to the circuit board. Put everything back into their places. Finally, light up the pilot and turn your water heater, which will fix the heater issue. 

4. Bad Thermocouple

A faulty thermocouple is a caveat that causes your water heater to go through the ‘high-temperature shutdown’ mode.

water heater bad thermocouple

The thermocouple may get faulty if dirt builds upon and around it. 

How To Fix:

Start with cleaning the thermocouple. Sometimes you don’t need to spend a single buck, and a little cleaning will do the trick for you. If the thermocouple doesn’t function after cleaning it, it would be best to replace it with a new one.

Make sure the thermocouple you will get matches up with the existing one. It will cost you only $10 to get a new thermocouple. Ensure the flame is clean and hits the rod in the center. 

5. Faulty Gas Valve

A faulty gas valve can also be the felon behind this water heater issue. Plus, a bad solenoid in the gas valve can cause your water heater to malfunction.

water heater faulty gas valve

It doesn’t matter what causes your gas valve to be defective, what matters most is you should change the gas valve.

How To Fix:

Replace the faulty gas valve with a new one to solve the issue. If you don’t know how to change the gas control valve, watch this tutorial to learn how to do it. 

How To Reset High Temp Shutdown On Water Heater?

Here is the step-by-step guide to reset the high temp shutdown on the water heater. 

  • First off, turn the knob from the off position to the pilot. 
  • By turning the knob to pilot, press down the button and quickly start hitting the striker. Now, look at the status light to look for the red light to come on and blink four times.
  • Make sure you hit the striker continually until you see the four flashes to come.
  • Once you see the status light to be litten four times, set the knob to the very hot position immediately. 
  • Count 10 seconds and move the knob to the hot position. 
  • Again, count 10 seconds and turn the knob to the pilot position. And recount 1-10. 
  • Now, we recommend you set the knob to your desired temperature level. And boom! You can find the burner to come on. 


Why is the water heater turning off?

Your water heater will keep turning off due to a bad thermocouple. A faulty thermocouple will turn off the gas supply to the burner and the pilot. Consequently, you can’t turn it on. 

Where is the reset button on a hot water heater?

You can find the reset button near the thermostat of your water heater. Some units may have a hidden reset button behind a removable metal panel. 

How do I know if my water heater thermostat is bad?

The water heater thermostat may get damaged if you get cold water after turning it on. 


Your water heater will lock out if the gas valve gets defective. Therefore, a faulty thermocouple and a bad thermostat are also responsible for the water heater high-temperature shutdown. 

You can easily overcome this issue by following the troubleshooting steps we mentioned. You can also fix the water heater problem by resetting the high temp shutdown on your water heater. 

Well, if you have any quire, the comment box is free for you. We’ll come back to you with the solution ASAP.

About William

William is the founder of Fireplacehubs.com. He has real life practical skills in fixing smoker & heating appliance issues. He loves to share his knowledge & helps others in fixing their appliances & saving their money. William firmly believes that anyone can repair his or her unit with the correct guidance & knowledge. See more at about us.

4 thoughts on “Water Heater High Temperature Shutdown [Reasons + Solutions]”

  1. Gas hot water heater was working fine. Now it does not ignite and light blinks 4 times meaning hot water shutdown? It lights pilot, but won’t ignite?

    • Hi Penny

      When you set the knob to pilot and notice the status light shows you 4 flashes, it indicates the water heater high-temperature shutdown issue.
      Well, your water heater won’t ignite because of a faulty gas valve that is disabled to recognize whether the pilot light is lit or not.
      Replace the faulty gas valve with a new one to solve the issue.

      Hope you will get the solution.


  2. The written instructions “How To Reset High Temp Shutdown On Water Heater?” below the video above worked perfectly for me. Thanks.


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