How to Enter the Diagnostic Mode on a Carrier Infinity Thermostat

Infinity thermostats are highly interactive devices that control temperature for Carrier-brand heating and cooling units. An Infinity thermostat controls the temperatures and fan speeds automatically according to day of week and time of day, based on times that you set. The diagnostic mode on an Infinity thermostat tests each component in the heating and cooling system to find malfunctions and supplies the owner with codes for repairs. Carrier calls the diagnostic mode "Checkout."

Step 1

Grasp the top of the flip-down door on the bottom of the thermostat. Pull the door downward. It will swing open on two hinges.

Step 2

Press and hold the "Advanced" button in the "Setups" area for at least 10 seconds. The "Install/Service" menu will appear in the digital screen.

Step 3

Press the "Scroll" button on the bottom to highlight "Checkout" on the "Install/Service" menu. Press the right button in the center of the thermostat to choose "Select." The diagnostic system will check each component of the heating and cooling system to verify they are installed and operating correctly. The "Equipment Summary" screen will list each item with "Yes" or the model number next to it to identify all components.

Step 4

Press the "Scroll" button to highlight "Service Info" and press the right side button to select this option. The screen will show each item on the heating and cooling system as it checks each one, and along with it will display any fault codes associated with system malfunctions.