Official Marathon electric water heater parts

How to fix your Marathon electric water heater when water gets too hot

First, adjust the thermostat setting to lower the water temperature if the thermostat is set above 130 degrees. The 120-degree setting is standard. If 120-degree water is too hot for you to use, try setting the thermostat at 110 degrees. Next, check the thermostats. The upper and lower thermostats in an electric water heater must fit snug against the tank to properly transfer heat in order for thermostats to detect the water temperature correctly. To check the thermostats, turn off the power to the water heater and remove the thermostat access covers. Check the thermostats' positions and adjust the thermostat brackets if necessary to press the thermostats against the side of the tank.

A thermostat that's stuck in the 'on' position will cause the heating element to stay on constantly, overheating the water in the tank. Or, if the element breaks, it can make contact with metal inside the water heater, creating a short-circuit. In that case, electric current flows through the element to the metal, causing the element to heat constantly. Examine the elements and replace an element if damaged.

Follow the steps in our troubleshooting video to figure out why an electric water heater overheats. Replace a thermostat if it's not regulating water temperature accurately.

Top-selling replacement parts for Marathon electric water heaters

• Heating element. The heating element, which is the heat source inside an electric water heater, extends directly into the tank, where it heats the water around it. Most electric water heaters have two heating elements, one at the bottom of the tank and one at the top. The bottom element handles most of the load, heating cold water as it enters at the bottom of the tank. The top element only operates to give water at the top of the tank a quick water-heating boost when needed.
• Temperature-pressure relief valve. The temperature-pressure relief valve (T&P) is a safety device attached to the side of the tank. If a thermostat fails, water inside the tank overheats and builds up pressure that can damage the tank and tank fittings. The T&P valve opens automatically and discharges water to relieve pressure if excessive pressure builds up in the tank.
• Thermostat. The thermostat monitors water temperature in the tank. When water temperature drops beneath the desired setting, the thermostat turns on the heating element to heat the water. When the water temperature in the tank reaches the set temperature, the thermostat shuts off the heating element.
• Drain valve. The drain valve fits at the bottom of the tank and allows you to drain water from the tank.