With the outside temperature dropping to bone-chilling levels, you absolutely do not want to be without a properly-operating furnace. While the majority of homeowners depend on gas furnaces to heat their houses, others have an electric furnace to keep the air temperature comfortable. The number one cause of an electric furnace not heating properly is a faulty heating element. Keep reading to learn a simple test you can perform to determine if your electric furnace’s heating elements are functioning normally or not.
How an electric furnace heats the air
While 47% of households in the U.S. rely on natural gas to heat the home (as opposed to 36% which rely on electricity to do the same), electric furnaces are still considered an efficient way to heat the air, providing consistent warmth without the need for combustion. Electric furnaces are also relatively easy to install and can be a good option for areas where natural gas or other fuel sources are not readily available.
So, how does an electric furnace heat the air in your home? It all starts with thermostat activation:
Thermostat Activation: When the temperature in the space being heated falls below the set level on the thermostat, the thermostat will send a signal to the electric furnace to start.
Electricity Flow: The electric furnace receives this signal and activates its heating elements. These heating elements are typically made of coiled wire or ceramic and are resistant to electricity. When an electric current passes through these elements, they generate heat due to the resistance, similar to how a toaster or an electric range works.
Heat Generation: As the electricity flows through the heating elements, they become very hot. Air from the surrounding space is drawn into the furnace through a vent or duct system using a blower.
Air Circulation: The blower circulates the cold air from the space over the hot heating elements. As the cold air passes over these elements, it gets heated up significantly.
Distribution of Heated Air: Once the air is warmed, the blower pushes it back into the space through the ductwork or vents, distributing the heated air throughout the home.
Thermostat Regulation: As the warmed air continues to circulate, the thermostat monitors the temperature. Once the set temperature is reached, the thermostat signals the furnace to shut off or reduce its heating output.
Cycling On and Off: As the temperature decreases again, the thermostat triggers the furnace to start the heating process again, repeating the cycle.
How to test an electric furnace’s heating element
To help determine if a heating element is faulty, you can test each heating element for electrical continuity – a continuous electrical path present in the component. Some furnace heating elements come as an assembly with the limit thermostat included, so you should test the thermostats as well. Here’s how you can do it:
- Your first step is to shut off the power to the furnace since you’re going to need to disassemble the furnace to access the heating elements.
- Next, remove the access panels from the front of the furnace.
- Locate the heating elements and unthread the mounting screws to release them. Disconnect the power wires from the terminals so you can fully remove the elements.
- Get out your multimeter and rotate the range selection dial to the lowest setting for ohms of resistance.
- Choosing a heating element, contact the black meter lead to one of the element’s terminals and the red lead to the other terminal.
- Observe the multimeter display. If the heating element has proper continuity, the meter display should indicate between 10 and 20 ohms of resistance. If the meter display shows no ohms of resistance, the element has no electrical continuity and you’ll know the part is faulty.
- Repeat the test for the other heating element, if applicable.
- Now, if the heating element has a limit thermostat attached, contact the black meter lead to one thermostat terminal and the red lead to the other terminal.
- Observe the multimeter display. The display should indicate that the limit thermostat has some resistance (usually in the 3 or 4 ohms range). If the testing shows that the thermostat has no electrical continuity, the part is defective and probably causing your furnace’s heating problem. You can often just replace the limit thermostat itself instead of installing a new heating element assembly.
Has your testing confirmed that a furnace heating element is faulty? Repair Clinic makes it easy to find the genuine original equipment manufacturer (OEM) replacement part you need to fix your electric furnace, whether your model carries the Bryant, Lennox, Goodman, Rheem, York, Coleman, Ruud, Heil, or Payne branding. OEM furnace parts are designed to work with your specific furnace model so you can be assured of a quality repair. To find the right heating element, limit thermostat, or any other component that works with your unit, simply enter the full model number of the furnace in the Repair Clinic website search bar. The result will be a comprehensive list of every replaceable part that matches your furnace. You can then use the “Part Category” and “Part Title” navigation filters to narrow that part list down to locate the exact part you need to fix the furnace.
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