Broken Worcester Highflow boiler (banging noises)

[tristan]

Hi,

Before I get an engineer out I suppose it would be nice to have some opinions.

I came home to find the boiler making just loud whirrrrrring noises, but without the pilot light on. I power cycled it off and noticed it had tripped its thermostat, so I reset that too.

Then this happens:

1. Boiler fires up, as normal... click click... pilot light.
2. Starts to heat the water (hot water from tap)
3. After about 15 seconds, banging noises come from inside. Loud.
4. The pressure gauge rises, and very soon afterwards the thermostat trips again.
5. Then it does the whirrrring noise which I encountered when coming into the house.

Any basic ideas? Ho hum :(

It's a Worcester Highflow 3.5 boiler.

Thanks,

Tris.

[Ed Sirett]

pump problem?

[Owain]

I don't know the boiler concerned, but my guess is (1) pump's gone, or (2) pressure vessel's gone.

Owain

[Mike Dodd]

I think I know where you're coming from - water boiling in the erm... boiler, and steam bubbling up the pipes, because of a lack of water flow?

Anyway, I had the same symptoms at the start of the year (mid winter) - caused by a build up of sludge in the radiators over the year finally settling in the heat-exchanger in the boiler, when the TRVs opened. Resulted in some of the water not being pumped through, and eventually the cast iron heat exchanger became brittle, bits started dropping off, and eventually ruptured the HE. New boiler time.

[tristan]

Well, the engineer is here at the moment.

Embarrasingly, bleeding a little bit of air from a radiator and from the boiler itself has restored full service. But he is checking to see if there is anything more fundamentally wrong which has caused it (Fixed call-out fee so I don't really have a problem with that!)

Tris.