High
A1 281 on Worcester Bosch Greenstar 12i System

Your boiler is struggling to move water around your heating system, which means it has stopped working to prevent itself from overheating.

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

Pump error: Pump stuck or running dry ▶ Check: – Primary system water pressure. – For air in the system. – Circulation within heating system. – Wiring and operation of the pump, replace if necessary.

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.

Find a Gas Safe engineer
Search the official register →

Related guides you might find useful

Banging / kettling / whistling noise

Each noise points to a different fault.

Read →

Boiler keeps cutting out

Lockout fault with a reset-needed pattern.

Read →

When to replace your boiler

7 signs repair isn't worth it anymore.

Read →