Unvented Expansion Vessel Keeps Failing

[stephenr]

I have a RM Stelflow 210 indirect unvented cylinder. Over the years it's been in, the expansion vessel has failed on 3 occasions. Any ideas what could be causing this?

cheers,

Stephen

 

[Best]

What do you mean by failed? Did it have to be replaced each time, or just serviced?
You have to have the unit serviced yearly and that should ensure the expansion vessel is working. Also the e.v. needs replaced every 5 or so years if you want it to remain reliable.
Can't really give advice on unvented units on open forum as they legally can only be serviced or installed by G3 qualified person.

 

[ShaunCorbs]

as above when was it last check / serviced, as could be a few things

also need to be G3 to work / service unvented cylinders

 

[Jones82]

I'd say either the control valve / pressure reducing valve is faulty or the expansion vessel is too small, it could also be an incorrectly installed system.

You are right to assume something is a miss, the vessel should not fail so often.