gas water heater thermostat pic3Is a gas water heater thermostat something you can fix? It is usually part of the gas valve and not set up for servicing. Most of the time, interest in the thermostat is to adjust the temperature of the water in the tank.

A defective thermostat will need to be replaced with the entire gas valve. See the article 'Troubleshooting Water Heater Gas Valves' for a discussion on this topic.

Not sure what your problem is? See the article 'Gas Hot Water Heater Troubleshooting' for more information and a listing of all of the issues associated with a gas water heater.

There are (3) key topics related to the thermostat. First is the 'Temperature Setting'. Second, before you blame your water heater, check the 'Gas Water Heater Tank Size'. The 'Water Heater Gas Valve' has your thermostat built into it. It can be replaced.

Hot Water Temperature

A bigger issue with the thermostat is setting it at the right temperature. Find out what the issues are and what you can do about them. When you have children and elderly individuals in your home it is important not to set the water temperature too high.

Wait, I usually mix the hot water with cold and the hotter the water the more showers and baths we can take. This is true, but there is a danger. Hot water from you tank at the highest setting can scald you and cause severe burns in less than a second.

What do you do if your gas water heater thermostat is bad? What is the best temperature to set it at? Are there other ways to get more hot water without raising the temperature? This article will help you answer all those questions.

Using Common Sense Header

What Can You Save? - The gas water heater thermostat is part of the gas valve. This part runs around $80. You will probably be looking at $100 to $125 for labor. For a gas valve that is working and just needs adjustment, you could be looking at $75 to $100.

How Hard Could It Be? - Adjusting a gas water heater thermostat is pretty easy. Changing a gas valve is a bigger job.These repairs will have a Difficulty Level of: A Bit of Work; These repairs require a Skill Level of: Handyman.

For and explanation of the terms in this section, see 'How to Use This Site'.

What Can Go Wrong? - Burns and scalding are a very real danger for a thermostat that is set too high. Be especially careful if you have children in the home. Being without hot water is another disturbing problem. Make sure you have the parts and the time before you tear into fixing your hot water tank.

Troubleshooting Gas Water Heater Thermostats

Adjusting the Hot Water Temperature

gas water heater thermostat pic2This is an obvious reason for using the thermostat on your gas hot water heater. Be very careful with raising the temperature on your water heater above 120 degrees. Scalds and burns are possible.

See the article on 'Gas Water Heater Temperature Settings' for information on the proper temperature setting for a hot water tank. The article also discusses the danger related to raising the temperature too high.

Not Enough Hot Water

Has something changed? Do you have more people using hot water? If that is the case, and you do not have enough hot water, you may need to consider a larger hot water heater.

A common complaint for a hot water tank is 'not enough hot water'. It may not be the hot water heaters fault. The article 'Gas Water Heater Tank Size' talked about the size of your tank relative to your household needs.

Thermostat on Gas Valve Is Not Working

The water heater thermostat is part of the gas valve. They cannot be replaced separately from the valve. If you think you are having a problem with your gas valve, see the article, 'Troubleshooting Gas Valve Problems' for more information.


The main thing to worry about with your gas water heater thermostat is the temperature setting. You do not want anyone in your home getting burned. Make sure that you have set your gas water heater thermostat at a proper setting.

To replace the thermostat you need to replace the gas valve. We gave you a link to find instructions on doing that. No other choice it comes as one unit. Did you find what you need? We hope so. Time to move onto your next home repair project.