The sound of a nonstop blower continuously circulating air through your HVAC system is more than simply an annoyance. The large electric motor that drives the blower is a significant contributor to monthly heating and cooling costs. Nonstop blower operation also adds more wear and tear to that expensive component.
In common operation, an HVAC blower runs in sync with furnace or air-conditioner cycles. When the thermostat signals for heating or cooling, the unit activates and the blower begins circulating warm or cool air. After the thermostat temperature setting is reached, the thermostat turns off the furnace or AC and the blower. A nonstop blower that never ceases circulating air may be a sign of malfunction.
Check the Fan Switch
The fan switch on the thermostat can run the blower continuously. If it is set to “On,” the blower will circulate air nonstop. The “Auto” setting of that switch, conversely, causes the blower fan to run only when heating or cooling cycles are activated. When the unit cycles off, the blower fan stops too.
What’s the Temperature Setting?
A thermostat temperature setting that is too high during furnace operation (or too low in AC mode) will cause the entire unit to run nonstop. Excessively high temperature due to continuous operation may eventually cause a safety sensor to shut down the furnace. Similarly, the AC compressor may overheat and also trigger a shutdown.
Calling in a Professional
The furnace limit switch controls the system blower, activating the fan only when the furnace’s burner temperature is correct. After the unit shuts down, it also runs the blower for a short time to cool furnace components. If the limit switch is improperly adjusted or defective, it may cause nonstop operation of the blower. Because the limit switch is an internal furnace component, diagnosis is a job for a certified HVAC technician only.
Ask Paitson Bros. service professionals for more about nonstop blower issues in your home. For more than a hundred years now, we’ve been your reliable source for trusted advice and experienced service for heating and cooling components.
Jeff Paitson is a third generation business owner who continues to run the business with the same values that have been passed down from previous generations since 1922.
Jeff’s belief is that the business belongs to Jesus Christ; therefore 10 percent of the company’s profits go toward the Maryland Community Church.
Jeff is a Terre Haute Chamber of Commerce member and in his spare time, he enjoys 
Ethan Rayburn is a lifelong resident of Terre Haute and a 2005 graduate of Purdue University.
An Eagle Scout, Ethan spent four years as a non-profit executive with the Boy Scouts of America before joining Paitson Bros. as a comfort advisor and later General Manager. In that role, Ethan has brought a renewed enthusiasm for customer care, integrity, value, and service to Paitson Bros. Heating & Air Conditioning.
Ethan enjoys singing and was a member of the Purdue Varsity Glee Club. He also enjoys playing and coaching soccer, spending time with his family and two young boys, and volunteering his time and resources with his church, Terre Haute First Baptist Church, which he has attended from a very young age.
Paitson Bros
1 (812) 232-2347
Serving the Wabash Valley, IN Area Since 1922