"AUTO" on the fan switch on your thermostat is the normal switch position for the fan control. How Should I Set the FAN ON-AUTO or FAN MAN-AUTO Switch on My Thermostat? There are advantages of running an air conditioning or heating blower fan continuously, and "AUTO" is the same as "AUTO which we discussed just above.ĭon't mix up the digital thermostat's display of the word AUTO regarding fan control with the display's use of the same word AUTO elsewhere in the thermostat's display window to describe the overall thermostat MODE setting which we discussĪt SWITCH FUNCTIONS on a Room Thermostat. On these thermostats "MAN" or "manual" is the same as "ON" in this situation. On some room thermostats the FAN switch may show positions labeled MAN and AUTO instead of ON and AUTO. On these switches located usually on the top, side, or bottom of air conditioning or heating thermostats, the "ON" position is not what you might think. The air conditioning or heating wall-mounted thermostat may have a fan or blower control switch with (usually) two set positions "ON" and "AUTO" or sometimes "MAN" or "AUTO" Running the fan "ON" all the time, which we like to do in lots of cases, distributes air and temperatures more evenly all the time in the home and produces less of a surge of heat or cool air when the heater or air conditioner actually turns on. Typically in the AUTO mode in a heating cycle the fan won't actually turn on until the furnace has warmed-up and the fan will turn off shortly after the furnace turns off at the end of a heating cycle. On a digital room thermostat when you press the "FAN" button, look closely at the thermostat's digital display - you should see the word AUTO (photo above left) or MAN (Photo above right) appear somewhere in the display to let you know which setting you have selected. At the end of a heating cycle when the thermostat is satisfied, the fan will automatically turn off.įan operation in an air conditioning system or heat pump operating in cooling cycle works similarly See CONTINUOUS BLOWER FAN OPERATION for reasons people may want to run the fan continuously.įAN switch set to: "AUTO" run let the fan be turned on or off automatically under control of the heater or air conditioner itself - when the thermostat asks for heat and the furnace warms up the fan will turn on. Our pencil points to the "FAN" switch or button in this case.įAN switch set to: "ON" will set the blower fan on your heating or air conditioning system run all the time, no matter what. Here we are using a Carrier™ digital thermostat for our examples. On most digital thermostats, pressing the "FAN" button repeatedly will cycle the fan control between two positions.
Thermostat fan control how to#
HOW TO SET the FAN ON-AUTO or FAN MAN-AUTO SwitchįAN Button AUTO and ON functions on Digital Thermostats.FAN Button AUTO and ON functions on Digital Thermostats.How does the FAN switch work on a digital heating or cooling thermostat and how should I use the FAN switch?
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Guide to Air Conditioning or Heating System Blower FAN ON-AUTO and FAN MAN-AUTO Settings on Wall Thermostats We also provide an ARTICLE INDEX for this topic, or you can try the page top or bottom SEARCH BOX as a quick way to find information you need.
Thermostat fan control series#
This article series answers most questions about central heating system thermostats & controls, troubleshooting, installation, inspection, diagnosis, and repair. How Should I Set the FAN ON-AUTO or FAN MAN-AUTO Switch on My Thermostat? What to do if the Blower Fan Runs Continuously and Won't Shut Off? How does the FAN ON-MAN switch work?FAN Button AUTO and ON functions on Digital Thermostats. We have no relationship with advertisers, products, or services discussed at this website.įAN ON OFF AUTO switch on thermostats, guide to setting, troubleshooting, repair: this article explains the use, setting, and adjustment of the FAN ON- AUTO button or switch or the FAN ON-MAN switch on room thermostats. InspectAPedia tolerates no conflicts of interest.