Medium Warning
No DHW But CH Works OK on Ideal Logic Max Combi

Your boiler is working to heat your radiators, but it is failing to detect when you turn on a hot tap or is unable to switch the water flow to your taps.

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

DHW turbine debris, flow rates, diverter valve motor wiring, or diverter head engagement.

What causes this fault?

This issue occurs when the boiler fails to sense water moving through the pipes when you open a tap, often due to a small internal sensor being blocked by grit or debris. Alternatively, the internal 'shifting' valve may be physically stuck or the motor driving it has failed, meaning the heat stays trapped in the radiators instead of reaching your hot water outlets.

Engineer required

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

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