British Gas 330

[nysk2008]

Went to see a mate today and he asked if I could have a listen to his boiler (make and model in title) when the stat calls for heat it seems to go through the start up procedure as per normal but it also makes loud revving/banging noises and then it calms down. This problem occurs day and night. I had no tools on me at all as only went for a cuppa but will be going back to investigate. From what my mate says the system has not been flushed so was thinking maybe circulation (he tells me the rad water is black) but would this cause the revving banging sound from cold? It was almost like some mild form of explosive ignition but I couldnt be sure, may be flue gases or unburnt gas?. It is a system boiler with a vertical flue and a few 45's on the flue route. Any ideas on this one? Would just like to know where to start?

 

[Puddle]

It is a re badged glowworm, strange that BG would not flush through system before replacing ??seems to be a issue to be address there !

Obviously a dirty system could cause problems and banging points to that but sounds like there could be burner pressure problem also

imho

 

[nysk2008]

Thx Puddle, do you have MI's for this or should I just work off of the glow worm HXI MI's?

 

[mfgs]

They are re-badged Glowworm HXI's as has been said. They are quite prone to blocking those heat exchangers due to very small passageways. I would be checking the pump first to make sure its working correctly to circulate the water. Make sure you check the graphite seal (G10) on the combustion chamber as its the same as on the Vaillants. Also look for any staining/rust down the very back of the boiler and on the bottom under the heat exchanger and the flue collectors and starting to crack on these, I have also come across a few with a dodgy seal connecting the collector to the heat exchangers. I always run my analyser around the top of the flue collector with these.