High
FAIL POINT E on Worcester Bosch 28 RSF

Your boiler is failing to detect that water is moving through the system, which is preventing it from safely starting your heating or hot water.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

Call an engineer soon

Book a Gas Safe engineer within 24 to 48 hours. Your boiler may be unsafe or could break down completely if left.

Technical description

Flowswitch assembly fault, multiway connector ST16 contacts 19 and 20 (pink wires) continuity issue, or damaged Red diode on control board.

Engineer required

This is a high severity fault. Stop using the boiler and call a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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