can I replace expansion vessel at rear of boiler.

[ianmcd]

Or just re-charge the existing expansion vessel properly

 

[CBW]

Or just re-charge the existing expansion vessel properly

Tbf mate, he did say it was pishing out, so could be from actual vessel, in which case, it’ll still pish out unless replaced

 

[ianmcd]

Tbf mate, he did say it was pishing out, so could be from actual vessel, in which case, it’ll still pish out unless replaced

Tbf mate where is it pishing out from? the EV seal or the schraeder valve ? the one worst diagnosed fault on a gas boiler is the EV, if the bladder is pinholed how can it "**** out" through the schraeder valve ? through the seam yes , in which case he wouldnt have heating or HW as the system wouldnt be able to be pressurised, just change the PCB

 

[Johntheo5]

Either can happen but very rarely together, air can gradually leak out through the schrader valve so the EV fills with water but wont leak anywhere, or the diaphragm can be holed, in which case the EV will again fill with water but if no schrader valve problem then no external leak.
Suggest pressing up a cold system to say exactly 2bar, the pressure will drop fairly rapidly if the EV is leaking externally, might also see signs of water dripping from the boiler.

 

[CBW]

Tbf mate where is it pishing out from? the EV seal or the schraeder valve ?

Dunno, wasn’t mentioned. I had one once though where it had a small pinhole in the outer metal and was leaking from there, not pishing out

 

[Neil Carroll]

Ive bought all the stuff for external expansion , just got to have the bottle to cut into the copper return pipe . ill give it a go tomorrow , just a thought , can I use a self cutting tap into the copper pipe just to confirm its totally drained? , then if it isnt at least I can control it , and then remove the self cutter and cut into pipe properly , I wouldnt be leaving it in .

Thanks for your ongoing help

the whole thing is a pain in the copper pipe.

 

[Neil Carroll]

Or just re-charge the existing expansion vessel properly

cant be recharged , water is coming out of vessel when valve pressed , its like a fountain.