Water in expansion vessel

[stonky]

On the advice I received from this forum about my heating problems. The first step was to check the pressure in my expansion vessel,and increase by using a footpump if found to be low.On removing the plastic cap and depressing the valve when attaching the footpump to the expansion vessel valve,there was a spray of water under pressure issuing from the valve. Would I be correct in saying this should not have happened and my expansion vessel is faulty. ANY HELP ON THIS MATTER WOULD BE APPRECIATED.

 

[oilman]

No option I'm afraid, replace it. (unless it was only a very, very small amount of water that could be condensation)

 

[stonky]

No option I'm afraid, replace it. (unless it was only a very, very small amount of water that could be condensation)

I have looked again and it appears to be a large amount of water, so no other option but to replace my expansion vavle. What would I expect to pay for an engineer to supply and fit, or is this something I could to myself.

 

[oilman]

You could replace it yourself on some boilers, the price will vary from £25-£70 for the vessel depending on size or shape. If you have the space you could fit an external one by adding a Tee connection on the flow pipe. You need one at least 10% of the total system volume. It can never be too big.

For fitting add £40, maybe more I can't say really....

 

[stonky]

Thanks oilman, replaced expansion vessel 3 days ago and combi pressure now stable.Engineer charged £84.

 

[oilman]

Was it an internal or external vessel, and what size? What type of boiler?

 

[stonky]

The expansion vessel was internal, about rugby ball size and was part of a Worcester Bosch 350 combi.