Low
305 on Worcester Bosch Greenstar CDi Compact

Your boiler is temporarily pausing to prevent damage because it has been switching on and off too frequently for your hot water.

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

Anti fast cycle mode for DHW

DIY fix possible

Wait 10-15 minutes for the anti-cycle countdown to completeEnsure hot water taps are fully closedCheck for dripping taps that may be triggering the boiler

Find a Gas Safe engineer
Search the official register →

Related fault codes

307View →

Related guides you might find useful

No hot water but heating works

Almost always a stuck diverter valve on combis.

Read →

Banging / kettling / whistling noise

Each noise points to a different fault.

Read →

Radiators cold at the bottom

Sludge build-up — needs flushing, not bleeding.

Read →