The part(s) or condition(s) listed below for the symptom Water heater too hot are ordered from most likely to least likely to occur. Check or test each item, starting with the items at the top of the page.
The thermostat determines the maximum water temperature setting. If the thermostat is defective, the water temperature may not be set at the proper level. To determine if the thermostat is defective, assess hot water temperature from the nearest faucet. If the water temperature is hotter than the selected thermostat setting, this indicates that the thermostat is defective. If the thermostat is defective, replace the gas valve and thermostat assembly. We recommend a set temperature of 120 degrees or fewer to prevent the risk of scalding.
A gas valve assembly that includes a thermostat could be responsible for the water heater getting too hot if the component malfunctions. The thermostat determines the maximum water temperature setting. If the thermostat is defective, the water temperature may exceed the set level. To determine if the thermostat is defective, assess hot water temperature from the nearest faucet. If the water temperature is hotter than the selected thermostat setting, this indicates that the thermostat is defective. If the thermostat is defective, replace the gas valve assembly. We recommend a set temperature of 120 degrees or fewer to prevent the risk of scalding.
If the heating element is shorted out, it will heat continuously, causing the water to get too hot. To determine if the heating element is shorted out, use a multimeter to test if the element is shorted to ground. If heating element is shorted out, replace it.
The thermostat determines the maximum water temperature setting. If the thermostat is defective, the water temperature may not be set at the proper level. To determine if the thermostat is defective, assess hot water temperature from the nearest faucet. If the water temperature is hotter than the selected thermostat setting, this indicates that the thermostat is defective. If the thermostat is defective, replace the thermostat. We recommend a set temperature of 120 degrees or fewer to prevent the risk of scalding.
Check the thermostat temperature setting. The thermostat dial may have been inadvertently moved or is just set too high and will need to be lowered. The recommended temperature setting is 120 degrees Fahrenheit. If the dial is set correctly but the water temperature is still too hot, the gas valve and thermostat assembly will need to be replaced.