My Worcester Bosch Greenstar HE combi boiler (Model: ZWB 7-27 HE combi) has developed a problem where 30 seconds or so after firing up it blows itself out with a huge bass rumble. It then goes through this process repeatedly until I turn it off. Does anyone know what could be causing this problem? I replaced the fan assembly a couple of years ago when it had the same problem but the fan seems to be working. Any help would be much appreciated. Thanks

Stephen Patman, April 2008

have you got a frozen external pipe?

David, January 2010

my boiler keeps viberating and is making funny sounds wot is the solution plus my preasure gause is down to 0

john d, January 2010

a frozen blocked condensate pipe causes prevents the boiler working. chop off the pipe outside the house and defrost the end with the kettle. solves the problems instantly. don't wait for british gas.

David, January 2010

The problem is definately a blocked condensate pipe,seen the problem many times

dan t, June 2009

I think it could be a blocked syphon, or pipe from the syphon, worth a check before getting involved with the gas supply

Steve Langley Heating, May 2009

Check the burner inside the combustion chamber it might be damaged

Paul, April 2009

Sounds Like the gas valve is incorrectly adjusted. A check with a Telegan for correct CO2 readings should verify this. I've not experienced this a Worcesters but is very common on Glowworms

DaveTheGas, August 2008