Low
305 on Worcester Bosch Greenstar 28CDi

Your boiler is temporarily pausing to prevent overheating while it manages your hot water supply, which is a normal part of its internal self-regulation.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

Monitor it

This is a minor fault. Keep an eye on it and mention it at your next annual boiler service. Reset the boiler and see if it clears.

Technical description

Boiler in hot water anti-cycle mode

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

306View →

Related guides you might find useful

No hot water but heating works

Almost always a stuck diverter valve on combis.

Read →

Boiler keeps cutting out

Lockout fault with a reset-needed pattern.

Read →

Is boiler cover worth it?

Break-even maths on monthly cover.

Read →