Air Conditioner Not Cooling? Check the Thermostat Fan Setting

If you turn on your central air conditioner, but only lukewarm air comes from the vents, don’t panic. It could be the thermostat is set incorrectly and just a simple flip of the switch will solve your problem.

Air Conditioner Not Cooling? Check the Thermostat Fan Setting

Your central air conditioner depends on the thermostat for knowing what to do, which in turn means you have the ultimate control over what happens. Most thermostats aren’t extremely complex, but fan settings can cause homeowners grief if improperly adjusted.

Your air conditioner relies on a fan to provide cooling air flow, and your system fan is controlled by the thermostat. Most thermostats have three fan settings–off, on and auto–and knowing which to use can mean the difference between no air, uncooled, damp air, and air that is refreshing, cool and dry.

The ‘off’ setting on your thermostat doesn’t provide any air flow at all, so most people recognize that setting will not help them during the hot days of summer. However, confusion often surrounds the use of ‘on’ versus ‘auto’, and this is where problems typically arise for homeowners.

The ‘on’ setting on a central air conditioning system thermostat causes the system fan, located adjacent to the evaporator coil where cooling actually takes place, to blow continuously.  This may sound ideal if you want maximum cooling; however, the evaporator coil is only cooling intermittently as the temperature setting on the thermostat permits.

That means the air flowing from the vents will be uncooled much of the time, and that will increase humidity and discomfort levels inside your home. The best setting for optimizing comfort is to place the fan on ‘auto’, as this will cause the fan to only turn on when the evaporator coil is also cooling. The ‘auto’ setting keeps air flow at its coolest temperature and also prevents humidity from building up inside.

If you have questions about your thermostat or air conditioner’s operation, or if your air conditioner still isn’t providing cool air after checking the fan settings, be sure to contact Tri County Air Care for help. We can help restore the cool flow of air you need and deserve.