Medium
2945 on Worcester Bosch Greenstar 8000 Style

Your boiler is rapidly turning itself on and off because it is struggling to move heat away into your radiators effectively, often due to a blockage or a closed valve.

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

Too many short heat demands in short time period

DIY fix possible

Check that all radiator valves throughout your home are fully openEnsure your heating system pressure is between 1 and 1.5 barBleed your radiators to release any trapped airReset the boiler using the reset button on the display

Find a Gas Safe engineer
Search the official register →

Related fault codes

2946View →

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 →