Low
CM120 on Baxi 400 Combi 2

This code is simply an information message indicating the current status of your heating timer or thermostat settings, not a system fault.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

Monitor it

This is a minor fault. Keep an eye on it and mention it at your next annual boiler service. Reset the boiler and see if it clears.

What the manual says

Manufacturer manual

Current operating mode in the zone (0: Scheduling, 1: Manual, 2: OFF (antifreeze), 3: Temporary)

From this model's manual
Verified against the Baxi 400 Combi 2 installation & service manual, page 56.
Plain-English guidance below. Severity, DIY steps, costs and parts are our interpretation to help you act, not text from the manual.

DIY fix possible

Check your external thermostat or boiler controller settingsAdjust your heating schedule or mode if you wish to change how the boiler is currently operatingPress the reset button only if the boiler has stopped working, though this code should not require a reset

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