Medium Lockout
2S02 on Ideal Logic Max Combi

Your boiler is confused by how your heating controls are wired and thinks it should be receiving two different signals to turn on at once.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

Book a service

This fault should be looked at by a Gas Safe engineer within the next week or two. It may get worse if left.

Technical description

2x Switched Live Mode selected.

What causes this fault?

This fault occurs when the boiler receives an electrical command to turn on from two different external sources at the same time, which confuses the system's logic. The most common reason is that the external thermostat or programmer has been wired into two separate terminals on the circuit board by mistake. It can also happen if a faulty smart home controller is sending conflicting signals to the boiler.

Engineer required

This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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Related fault codes

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