How to Replace the Heating Coil in Your Furnace

A heating coil.
  • 2 hours
  • Intermediate
  • 45
What You'll Need
Heating element
A screwdriver
A neon light circuit tester
A socket
A garden hose
A ratchet

A heating element is an important device that converts the electric current into heat energy. These are usually utilized in electric stoves and ovens, water heaters, and other equipment that uses electricity to produce heat. Electric hot water heaters, for example, have two or more heating elements that are controlled by either a thermostat or an independent temperature controller. As you continually use the furnace, water minerals will eventually wear away the heating element and cause it to eventually fail.

Step 1 - Uncover the Heating Element

Make sure to turn off the electricity to the furnace before doing any work. Turn off the two-pole circuit breaker or just simply pull the two fuses of the power source of your furnace.

Now use the screwdriver to remove the external metal cover that hides the heating element to be replaced. Remove the screw located on top of the furnace cover and pull out the cover from its shell. Also, take out the small insulation covering which shields the heating element. Draw away the plastic cover that protects the element’s terminal screws. Be very careful and do not let your fingers touch the screws.

Step 2 - Test and Drain the Furnace

Using the neon light circuit tester, let its tips touch each of the terminal screws. If the light in the tester turns on then there is still electricity supplied. If this happens, double-check the breaker to the furnace. Consider turning off power to the entire house if necessary. Once the circuit tests as off, use the screwdriver in removing the two wires away from its screw terminals.

Close the valve that supplies water to the furnace and attach the garden hose to the drainage valve. Run the water outside or into a bucket or sink, but make sure the hose is level or going down from the valve so that the water will run out. Open the drainage valve and drain the tank.

Step 3 - Install the New Heating Element

After draining the furnace of water, you can remove the heating element. Depending on how it is attached, you may use the ratchet to help you pull out the element from the tank. Attach the new heating element into the water tank and make sure that the rubber gasket is properly positioned around the metal flange. Keep the new heating element in place by returning the screws, or screwing it clockwise to how it was originally positioned and tighten it to keep it sealed.

Step 4 - Finish the Process

Return the electrical wires to the screw terminals, close the lower drain, close the hot water valve, and open the cold water valve to allow the tank to fill completely. Check for any leaks surrounding the new heating element. Replace the plastic insulator with fiberglass insulation. Replace the external cover. Remove the garden hose from the lower drain valve. Turn on the electrical power of the furnace as the last step.

Proceed to open the hot water spigot and make sure to get rid of excess air from the hot water tank before closing it. You may check on the furnace’s hot water production in an hour.