Expansion valve problem?

[waldomeyer]

Hi all

Doing a friend a favour and sorting out a tundish discharge on an unvented cylinder.Not a jobbing plumber,normally just do refurbs so most of the kit i work with is new out the box.

Its an Ultrasteel cyl by copperform and has a continous discharge via the tundish.The arrangement is within the regs spec and it seems to be the expansion relief(pressure relief) valve discharging as the water is cold and I can clearly hear the exp. valve discharging water. All the controls are to the manufacturers specs and according to their fault finding chart,the exp. valve is the fault. I am a bit concerned that the expansion vessel is possibly causing a problem as I cant get a pressure reading from it or even let any are out,the valve looks to be stuck.It does however conform to the sizing and pressures according to the labels.

My next step is going to be to replace the exp and balancing valve (they`re a unit) and then take it from there.

I dont want to run the costs up too high but it seems like a process of elimination os the only way. Not being a jobbing plumber,I have no idea what to charge for the job,besides materials. It is an aquantance Im doing it for so dont wat to rip them off but then again,what would a full charging plumber be asking for this kind of thing? It seems easy enough to replace the valve to the customer but its a case of knowing what to look for re a problem.Someone initially told her it was a faulty f.o.v in the cistern,I soon found she doesnt have one though!

pls help!😕

 

[helpsy]

You can only work on unvented systems if they are under 15 litres(without being ticketed)

 

[migoplumber]

it is dangerous to work on unvented cylinders. it does sound like the t.p.r.v. (not just a p.r.v.) is blowing off.
its a simple job to do, however you should really advise your friend of the legalities involved and that you shoudnt do the job.
its not an expensive thing for a qualified engineer to do, and your mate will appreciate you explaining the possible life/death explosion vaporization of his family members.

good luck

shaun

 

[david williams]

if you are not qualified to do this work dont!!!!! if you cause damage or injury you could find yourself fined or even imprisoned.