Air Handler Fan Not Working: Causes and Solutions

If your air handler fan is not working, you’re either too hot or too cold. An air handler pairs with a heat pump to heat and cool your home, while an air handler paired with an air conditioner cools and dehumidifies your home.

When the air handler blower fan stops working, there are a few things you can do yourself to see if you can resolve the problem.

If the fan in your air handler is not working, check the filter. A clogged filter can cause all sorts of problems. Proper airflow is essential for your HVAC system to operate. If the filter is dirty, change it and see if that fixes the problem. If not, keep reading and check out our HVAC air filter maintenance guide.

Make sure the fan setting is set to ON or AUTO. It might have accidentally been set to OFF. If your thermostat has batteries, you may need to change them. If you have a bad thermostat, you’ll need to replace it.

Another thing you can do yourself is check to see if the air handler has power. There may be something that looks like a light switch right next to the air handler. Make sure it’s in the ON position. Next, check your circuit breaker box. If the breaker is flipped, leave it alone and call your HVAC company. It flipped for a reason, and turning the system back on without getting it checked out could damage the system.

Now, we get into the more technical issues that require a visit from an HVAC technician to troubleshoot and fix. The inside of your air handler contains a control board, relay switches, wiring, and more. A problem with a relay switch or the control board will require professional repairs.

Loose or frayed wiring could cause the problem as well. An HVAC professional can determine if this is the cause of an AC or heat pump air handler fan not working.

The air handler fan is powered by the blower motor, which has a run capacitor. If the capacitor is bad, the fan will stop running. Once again, troubleshooting and fixing this issue is a job for a trained HVAC professional.

The air handler blower fan may not be working because of a problem with the blower motor itself. The motor can overheat and shut the unit down, causing the fan to stop. Overheating can be caused by a faulty run capacitor, a clogged filter, and other issues.

When the air handler fan motor is not working, you need to shut your system off and call for HVAC repair.

Finally, the air handler fan may stop working if you have a frozen evaporator coil. It struggles to pull air through the coil and can overheat and shut down. If the fan isn’t working, it can cause the coil to freeze. If you have a frozen evaporator coil, turn the system off at the thermostat or circuit breaker box and call for HVAC repair.

To help keep your heating and air conditioning system running smoothly, change the air filter every 30-90 days based on the quality of the filter. Keep the outdoor unit clear of debris and encroaching shrubbery.

Schedule AC maintenance every spring and heat pump maintenance in the spring and fall. During a professional HVAC system maintenance visit, the technician will check the outside unit as well as the air handler for safe and efficient operation.

Anne Fonda, Content Writer at Trane Technologies

A Content Writer with Trane Technologies, Anne Fonda researches topics and writes for Trane® and associated residential HVAC brands. She works in collaboration with Trane Technologies subject matter experts, offering easy-to-understand, informative content on complex topics. Her goal is to help consumers make informed decisions on the products and services they need.

She has written for HVAC and other service provider websites for over 16 years. Before transitioning to web content writing, Anne had a 14-year stint as an award-winning journalist. She graduated cum laude from the University of Missouri-Columbia School of Journalism. When she’s not working, Anne enjoys playing word games, reading, gardening, spending time with family, and visiting gardens and museums.

Expert review by Kimberly Sexton, Senior Systems Engineer

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