Safety first: For wired thermostats, isolate power before removing covers.

Steps:

Review installation manual: Check the Danfoss Ally manual for the correct configuration parameters for your system (radiator, underfloor heating, electric floor, etc.).
Enter installer menu: Access the installer or advanced settings menu and verify sensor selection (internal, external, or combined), control algorithm, and maximum floor temperature limits.
Correct parameters: Adjust settings to match the actual wiring and heating type. Save and exit the installer menu.
Factory reset if needed: If the error persists, perform a factory reset and repeat the guided setup from the Ally app.

Display shows 'CF' or configuration error; thermostat does not follow expected heating mode or sensor selection.

Possible Causes