How to adjust water heater temperature

Image of two water heater temperature dial settings

Did you know your water heater can cause burns if the temperature is too hot? How do you know if your water heater is too hot? The easiest way to test your water temperature is to run hot water from your faucet for 3 minutes and fill a glass of water. Insert a thermometer into the water and check the reading, if its is over 120 degrees the water is too hot and can potentially cause burns.

As you use your water heater, mineral and scale buildup can cause the settings to be off. If your water temperature is too high you can adjust the setting on the water heater. Most water heaters have a dial on the valve with letters (A, B, C), or the words warm and hot printed on it and with small notches to indicate the setting. The valve is a mechanical valve and getting an exact temp is nearly impossible by looking at what is on the dial. So it’s best to make an adjustment and wait 3 hours before testing your water again with a thermometer. Its also a good idea to do one final test in the morning after it has sat over night. If the valve doesn’t respond to adjustments or causes too much temperature change then the valve could be bad. In that case it may be time to call a plumber to see if the gas valve or the water heater itself needs to be replaced.



What if I don’t see a dial on my water heater

If you don’t see a dial on your water heater or just have a panel like the one pictured here, then you have an electric water heater. You can still test your water the same way as described above. However, in order to adjust the temperature on an electric water heater we recommend contacting a professional plumber. TLC does not recommend attempting to adjust the temperature on your own. If you are experiencing problems with your water heater temperature its best to contact a professional.