Change the Thermostat in an Electric Water Heater
Electric water heaters use two thermostats to control the hot water temperature in the tank. When one thermostat goes bad, you should change both thermostats at the same time. Changing the thermostats in your electric water heater will not require draining the water tank. The thermostats mount to the side of the core tank. The thermostats operate through a bi-metal switch that is behind the thermostat. When the heater tank reaches a certain temperature, the thermostat will cut off power to its corresponding heating element. Does this Spark an idea?
Instructions
1. Go to your home electrical panel box and turn off the circuit breaker to the hot water heater.
2. Go to your water heater and locate the two access panels that cover the upper and lower thermostats. The access covers will be on the side of the water heater. Remove the screws securing the covers with a Phillips head screwdriver and pull back any insulation covering the top of the thermostats.
3. Loosen the terminal screws securing the wires to the upper thermostat and limit switch with the Phillips head screwdriver. The limit switch is the the block portion above the thermostat and usually has a red reset button. The upper thermostat attaches to the limit switch. It is a good practice to replace the limit switch when replacing the thermostat.
4. Place small pieces of masking tape around each wire and mark the location of each wire on the tape with a pencil. This will help when you install the new thermostat. Pull the wires away from the thermostat and the limit switch. Remove the mounting screws securing the thermostat and the limit switch and pull both off away from the water heater.
5. Loosen the two screws securing the wires to the lower thermostat. Pull the wires off the terminal screws and remove the mounting screws securing the thermostat to the water heater.
6. Take both thermostats and the limit switch to a plumbing supply facility for replacements. You should also write down the voltage of your water heater as well. The voltage information is on the end of the elements that mount above the thermostats.
7. Position the lower thermostat into place and secure with the mounting screws. Bend the ends of the wires around the terminal screws and tighten the terminal screws to secure the wires.
8. Place the upper thermostat and limit switch into position and secure with the mounting screws. Bend the ends of the water heater wires around the appropriate terminal screw according to the location you marked on the tape. Tighten each terminal screw to secure the wires and remove the tape.
9. Adjust the thermostat temperature settings according to the instructions from the manufacturer. Do not set the temperature above 140 degrees Fahrenheit. Most applications do not require temperatures above 120 degrees Fahrenheit.
10. Place any insulation you removed back over the thermostats and secure the access covers to the water tank. Turn the circuit breaker on to supply power to the water heater.
Tags: limit switch, water heater, screws securing, mounting screws, terminal screws, thermostat limit