The HVAC blower in your central system is a vital component that maintains comfort and efficiency in your home. Most of the time, blower function is linked to the cycles of the furnace or air-conditioning components. When the thermostat signals for heating or cooling, the blower and the specified component turn on. When the programmed thermostat temperature is achieved, all units turn off.
Or not. An HVAC blower that runs continuously even after the furnace or AC cycles off can raise monthly operating costs as well as impose excess wear and tear on the expensive blower motor. Here are some of the reasons why an HVAC blower might go nonstop without your permission:
The thermostat setting is wrong. The thermostat actually includes a setting to make the blower run continuously. If the thermostat fan setting is “On,” the blower will continue circulating air even after the heating or cooling cycle is over. Change the setting to “Auto” and the blower will turn on and off normally, in sync with the furnace or AC cycles.
Extreme temperature setting. An excessively high or low temperature setting may keep the AC or furnace running continuously, causing the HVAC blower to run all the time.
Fan limit-switch issues. This requires troubleshooting by a qualified HVAC technician. The fan-limit switch in the indoor air handler turns the blower on when heated or cooled airflow has reached programmed thermostat settings, then turns the blower off a few moments after the furnace or AC unit shuts down. Some of the potential problems involving the fan-limit switch include:
- A manual button at the fan limit switch that controls continuous fan operation may be activated.
- The limit switch itself may be defective.
- Shorts or disconnected thermostat wiring may cause the blower to run continuously.
Consult the service professionals at Paitson Bros. about any issues you may have with HVAC blower operation. After 100 years of service to the Terre Haute community, we’re already working hard in year 101.
Paitson Bros
1 (812) 232-2347
Serving the Wabash Valley, IN Area Since 1922