Medium Warning
POINT F on Worcester Bosch Highflow 550 CDi

Your boiler's internal pump is failing to run its normal cooling-down cycle after you turn the heating off, which could cause the unit to overheat.

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

Pump does not continue to run for approx. 5 minutes when central heating or programmer is turned to OFF

What causes this fault?

This fault occurs when the boiler's internal computer fails to keep the pump running after the burners have turned off. The most common reason is a failing circuit board that is no longer sending power to the pump, or a pump that has become seized and cannot complete its essential cooling cycle.

This fault often becomes apparent in the spring when the central heating is used less frequently, causing older pumps to seize during longer periods of inactivity.

Engineer required

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

Find a Gas Safe engineer
Search the official register →

Related fault codes

POINT EView →POINT HView →

Related guides you might find useful

Banging / kettling / whistling noise

Each noise points to a different fault.

Read →

Boiler won't turn on — 9-step checklist

Work through these before the call-out.

Read →

Boiler keeps cutting out

Lockout fault with a reset-needed pattern.

Read →