4 Ways Thermostats Can Cause Furnace Or Blower Fan To Continuously Run

A furnace or blower fan going at all times creates a strain on your furnace and a drain on energy. Does the blower fan stay on even if the furnace is off? Does the furnace never seem to stop? If your furnace or blower fan stays on for too long, or if it never stops, your thermostat may be the cause.

1. Your Thermostat Fan Setting Is Wrong

Many thermostats have a fan setting. If you turn that feature on, the blower fan will stay on whether the furnace is on or not.

If you switch the setting to auto, the thermostat will know to turn the blower fan off when it's not needed. Your thermostat may have additional settings for the blower fan, so make sure to check and see if those settings can make a difference.

2. Your Thermostat Is Turned Up Too High

Sometimes all you need to do is turn the thermostat down. Automatic settings or a little forgetfulness can sometimes lead to a thermostat set higher than you would want. Your furnace will continue to pump out heat and the blower fan will continue trying to distribute it.

Try turning the thermostat down and see if the blower stops. If it doesn't, don't panic; check for another potential thermostat issue.

3. Your Thermostat Is in a Bad Location

Thermostat location matters more than many people think. Most thermostats check the temperature of their immediate location. If the thermostat sits in an area that's cooler than the area you're trying to warm up, it may keep the furnace or blower fan going.

The thermostat will want to get the surrounding temperature to match the temperature you set. That continuous work will also add premature wear and tear to your furnace. You can have a professional relocate the thermostat.

4. Your Thermostat Needs Repair or Replacement

The thermostat in your home has a very close relationship with all your HVAC equipment. An old thermostat or one in disrepair can create a plethora of problems. If the furnace blower runs nonstop, you may need your thermostat repaired or replaced.

Checking on your thermostat is one of the first things you should do when dealing with an always-on blower or furnace. This is one of those things you can verify as the problem or eliminate as the problem without too much effort.

Of course, if the issue isn't the thermostat, then you should contact a professional furnace repair contractor. Sometimes the blower fan itself can require replacing or some wiring issue can lead to the furnace staying on. Once you rule out the thermostat, a local furnace repair service can help you figure out the rest.