How to Change a Honeywell Thermostat From C to F

Honeywell's 7-day and 5-day programmable thermostats have the ability to be read in either Celsius or Fahrenheit. Changing a Honeywell thermostat from Celsius to Fahrenheit requires placing the thermostat into programming mode. Each thermostat has a slightly different way for the homeowner to switch from the Celsius reading to the Fahrenheit reading. When you first enter programming mode, the thermostat should automatically default to Fahrenheit. A couple quick button pushes will bring the reading to Fahrenheit if the thermostat does not automatically default.

7-day Programmable Thermostat

Step 1

Press and release the "System" button on the left side of the thermostat display screen. Press and hold the blank center button on the row of buttons on the bottom of the display screen. When the display screen changes, release the button. The display will have two numbers showing, one three-digit number on the left and a two-digit number on the right.

Step 2

Press the directional "Up" button next to the three-digit number. Press and release the button until the three-digit number reads "320." The number on the right becomes a "0."

Step 3

Go to the directional keys by the right side number on the display screen, if the number on the right is a "1." Press the "Up" button once to advance the number to "0." The number "1" on the display indicates Celsius while the "0" indicates Fahrenheit.

Step 4

Press and release the "Done" button on the lower left corner of the display screen.

5-day Programmable Thermostat

Step 1

Press the two directional buttons simultaneously for three seconds. The display screen will show one large number and one small number. The program defaults to display a large "1," which is the temperature reading function.

Step 2

Press and release the "Up" button if the smaller number is a "1." The number should change to "0" for Fahrenheit.

Step 3

Leave the thermostat alone for 60 seconds and it will exit programming mode.