Electric Furnace Troubleshooting: Breakers, Elements, and Airflow
Quick answer: this page is for electric furnace troubleshooting: breakers, disconnects, thermostats, blower operation, sequencers, limit switches, and heating elements. If the furnace simply stopped working and you need a general repair path, start with John Owens furnace repair service.
Electric Furnace Troubleshooting
Electric furnaces heat air with electrical resistance elements instead of gas burners. That makes the troubleshooting path different from a gas furnace, oil furnace, or heat pump. This guide is for electric-furnace symptoms such as a tripped breaker, no heat from the elements, weak airflow, a blower that will not start, or a system that cycles in a strange pattern. For a broad no-heat emergency, a gas smell, or a furnace that has fully stopped in cold weather, use the general furnace repair page instead.
Common Electric Furnace Issues
Warning signs of a malfunctioning furnace can include:
- Unusual noises, such as banging or clanking sounds.
- Inconsistent heating, with some rooms’ temperature feeling colder or hotter than others, or a weak stream of air coming from the vents.
- Cold air comes out when the heater is running.
- Increased energy bills, indicating a decrease in system efficiency.
- Frequent short cycling of your heating system.
Before You Open an Electric Furnace
Before opening an electric furnace, shut power off at the disconnect and breaker. Do not bypass safety switches, work on live wiring, or replace internal electrical parts unless you are trained to do it safely. A multimeter can help a qualified person test the thermostat circuit, blower motor, limit switch, control board, sequencer, and heating elements, but it should not turn a homeowner into an electrician.
Wear protective gear like gloves and safety glasses when working with electrical components, and ensure the area around the furnace is clear of debris and combustible materials. Be sure that you have the manufacturer’s recommendations on hand for your specific furnace brand as well before you begin work.
Electric Furnace Parts To Check
The electric-furnace checks below are focused on the parts that most often separate electric units from gas furnaces:
- Air filter
- Blower motor and fan
- Electrical ignition
- Supply and return heating ducts
- Thermostat
- Limit switch
- Heating elements
- Control board
Thermostat and Low-Voltage Signals
If the electric furnace does not start, starts late, or cycles in a pattern that does not match the room temperature, begin with the thermostat and low-voltage call for heat.
- Check the thermostat’s batteries and replace them if necessary.
- Ensure the thermostat is set to heating mode and the temperature is set high enough to trigger the furnace.
- Check for loose or corroded connections between the thermostat and the furnace.
- Make sure the thermostat settings are properly programmed.
- Consider upgrading to a programmable thermostat for improved energy efficiency.
- If it is positioned improperly in direct sunlight, for example, it may not be able to get an accurate reading, so you will have to relocate it.
If the blower runs constantly, make sure the thermostat fan switch is set to auto, not on. If the electric furnace still does not respond, John Owens can check whether the problem is the thermostat, the control board, a relay, or another furnace component.
Breaker, Disconnect, and Furnace Power
Electric furnaces draw heavy electrical load, so power problems are common. Start with the safe checks before assuming the heating elements have failed.
- Check the circuit board for signs of damage or wear, such as burn marks or frayed wires.
- Check the breaker panel to make sure the furnace breaker switch is turned on.
- If you find that the breaker switch is still on, turn it off and check to see if there is a fuse within the furnace that blew out.
- Make sure the power switch for the furnace (which typically looks like a regular light switch on the wall near the unit) is turned on, giving power to the system.
Limit Switches, Sequencers, and Safety Controls
An electric furnace relies on safety controls to keep the blower, heating elements, and cabinet temperature in range. When one of those controls fails or trips, the unit may blow cool air, short cycle, or stop heating.
- Look to see if you have a safety switch on the door of your furnace, which is meant to shut off the fan and burner when you open the door. This switch can malfunction and shut the fan and burner off on its own. You can use a multimeter to make sure the switch is working.
- The blower motor also has a safety switch that may need to be reset. It may be because the motor needs to cool off.
- The limit switch is a safety feature that is there to prevent the furnace from overheating. If this switch has tripped by accident, it will stop the furnace from running, or it could cause the blower to run but with no heat coming out.
- A furnace sequencer is what turns the heating elements on and off in a specific sequence that doesn’t overload the breaker. A faulty sequencer can cause overheating or trip the furnace breaker.
Blower Motor and Fan Problems
Issues with the blower motor can lead to your electric furnace not running at all, the fan blowing weakly, not enough heat coming from the system, or short cycling.
- If the blower motor is running weakly or it has failed completely, that could cause the furnace to not power on at all. using a multimeter could test if there is power getting to the motor. If there is a safety switch and it has not tripped, there is power getting to the motor, and it’s still not running, it will need to be replaced.
- The blower belt may also need to be tightened or replaced if it is broken. A loose or broken blower belt causes the blower fan to turn less and not be able to circulate the hot air through your house. You can remove the access panel and check the belt number to get the proper replacement if needed.
- A blower wheel that is dirty can also be an issue. It will reduce airflow as well as increase your energy usage since your system will use more electricity to try to power the unit and provide enough heat. This can be avoided by changing the air filters regularly and cleaning off the blower wheel if debris begins to build up.
- It is possible the blower motor or fan needs to be lubricated in order to turn at an adequate speed.
Airflow and Sizing Issues That Feel Electrical
- If your furnace is too small, it will not be able to adequately heat your space. Furnaces range in size, and when installing a furnace, you have to know the BTUs and how many square feet each furnace is able to heat. This determines how efficiently the furnace will be able to send the heated air through the ductwork of your house until your space is at your desired temperature.
- Faulty electrical parts can cause weak or cold air to come out of your furnace unit, including the safety switches, power, thermostat, heating elements, motor, and more. Using a multimeter, you can test each of these parts to see if power is getting to them, or you can even use a flashlight to do a visual inspection and see if anything looks burned or melted.
- A clogged air filter can be a common reason for issues with the furnace. A furnace filter is there to catch any dust and pollutants from circulating through your air ducts and into your air. Over time, it will become filled with dust and make it difficult for your system to run efficiently if not regularly changed, since the air handler will have to run more to try to get past the blockage and reach the desired temperature. Changing dirty air filters is the quickest and easiest electric furnace service you can perform and can save money in energy bills by allowing the hot air to run unobstructed through your ductwork.
- Look at the heating elements to see if they look corroded or cracked. Instead of a gas valve and pilot light, in an electric furnace, the heating elements create heat by electric currents passing through them, and they can become worn down over time. If they need to be replaced, you will have to call an electric furnace repair specialist.
- If your vents are blocked or closed, this can severely restrict heating and lead to your furnace using a lot more energy than necessary. If a vent is obstructed in some way, the furnace will try to power more heat to get that area of the house to the correct temperature, which could lead to less efficiency and overheating.
Ready to get things fixed? Schedule your service today or give us a call and we’ll be happy to help.
Maintenance That Helps an Electric Furnace
Electric furnaces do not have a gas burner, combustion chamber, or flue pipe, but they still need clean filters, clear airflow, sound wiring, working safety controls, and proper blower operation. Maintenance should support electric-furnace reliability without turning this page into the main furnace repair or furnace maintenance guide.
DIY Furnace Maintenance Tasks
- Shut down your furnace system at the main circuit breaker.
- Clean out the access panels with a vacuum.
- Wipe down the blower fan blades and clean off the motor.
- Replace your air filter. The furnace filter is usually located in the blower compartment. Remove the old filter and insert the new filter facing the correct direction before replacing the filter cover. This should be done every 1-3 months.
- Clean out your air ducts using a shop vacuum, brush, and microfiber cloth. Remove the vent covers and insert the brush inside to loosen all the debris before inserting the nozzle of the vacuum inside and sucking out the built-up dirt within the duct. Wipe down the vent covers as well.
- Check the thermostat’s batteries and replace them if necessary. Set your thermostat to 68 degrees Fahrenheit when you’re awake and in the house, but lower it when you are sleeping or when you leave the house for a period of time.
- Perform a visual inspection of the heating elements, calling an HVAC professional if they look corroded or cracked.
- Ensure the area around the furnace is clear of debris and combustible materials.
Have a question or need a hand? Reach out anytime. You can book a service or talk with our team.
When To Call John Owens
Schedule service with a licensed HVAC contractor when the breaker keeps tripping, the blower will not run, the elements do not heat, the cabinet overheats, or the thermostat checks do not solve the issue. John Owens can inspect the electrical furnace controls, blower, filters, duct airflow, and heating elements before recommending a repair or replacement.
Changing the heating elements is a job for a furnace professional because there are dangerous components, and they require exact work to install and ensure they are operating safely. This is usually the same as any other electrical component of the furnace. Some electrical wiring or panel issues may require an electrician, but furnace controls, airflow, heating elements, and system diagnosis should start with an HVAC technician who works on the whole heating system.
The safest homeowner work is limited to filter changes, thermostat settings, vent checks, and keeping the furnace area clear. If the issue involves wiring, controls, heat strips, a sequencer, a limit switch, or repeated breaker trips, stop and schedule service.
John Owens Services, Inc. is a professional in furnace maintenance in Petaluma, Santa Rosa, San Rafael, and the surrounding areas that can install, repair, and service all different types of air conditioning and furnace systems, from electric and gas to heat pump systems. Whether it is maintaining older units or installing a new furnace, we can help ensure you have warm air throughout the heating season. We can also clean and seal ductwork and test your indoor air quality to ensure your HVAC system runs at peak efficiency. We even have a free online heating and air conditioning quote tool, so you can see the cost of any furnace maintenance or installation job beforehand. If you are in need of electric furnace repair, gas furnace maintenance, heat pump services, or any other furnace service, we are the HVAC technician to contact!
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