The temperature outside has begun to drop overnight, to the point that perhaps your family requires a little warmed air to help keep them comfortable. If your residential heating system is working properly, when your house hits your desired cozy temperature, your heating system should stop running. Once the temperature falls below the pre-set threshold, your heating system should kick back into gear, and get to pumping warmed air. If your home heating system is continually running, it can indicate a problem, and I’m not just talking about your outrageous energy bill. Here are some common reasons your heating system may continue to run and what you can do about it.
Step 1: Check Your Thermostat Settings
If you have your thermostat set at a comfortable room temperature and your living space has reached that desired temperature and your home heating system is still pumping warm air, check your thermostat. Set the thermostat to a temperature that is lower than the current room temperature and wait three to four minutes. The blower fan should stop running within five minutes. If the blower does stop running, it is likely that you have your temperature set too high and your heating system is in overdrive attempting to reach and maintain the set temperature. If your heating system continues to run despite it being warmer than the set temperature, try tip number two.
Step 2: Ensure the “Fan” is Set to “Auto”
If your fan switch is set to “On,” the blower will continue to run because that’s what you’ve instructed it to do! When the fan is set to on, it will continue to run regardless of whether or not your heating system is heating the air or not, or whether or not the air temperature has reached its goal. If you switch the fan to “auto,” it should stop running once the pre-set air temperature has been reached. If it doesn’t, try tip number three.
Step 3: Check the Fan Limit Switch
The fan limit switch is located under your furnace’s hood and is the main control for when the furnace blower turns on and off. Within the switch is a sensor that monitors the temperature of your burner assembly. Once the burners are hot, the fan turns on to disperse the warm air. Once the desired temperature is reached, the blower should shut off. If the desired temperature is reached in your house and your furnace is still blowing, check the limit switch. If the limit switch has been changed to “manual override,” you will need to tell the furnace when to stop blowing. If it is in manual override mode, just flip it back to auto (which may actually be a compressed white button that needs to be released) and you should be good to go. If it is switched to auto and still blowing, you may have a faulty switch that needs to be repaired or replaced, which I highly recommend leaving to the professionals.