Possible Expansion Vessel problem?

[Simon F]

the charge pressure in the expansion vessel should be 0.7 bar, the manufacturer may specify different. this needs testing without the pressure in the system affecting it, ie boiler flow and returns closed and drained. you really should get someone registered to test this for you.

 

[heliotrope]

Ok, 0.8 is not exessive for this boiler, just be sure that system completly depressurised before
pumping up. (0.5 to 0.6 the optimum).

No isolators turned off etc.


Although no water coming from valve it could still be split bladder in vessel.

This would need replacing or (easier) a new vessel fitted remote from boiler.

 

[shamilt1]

Okay, got my pressure vessel sorted- held open the PRV ( as its leaking anyway) and pumped up to the correct pressure. This has sorted out the pressure problem and it now only rises to just below 2 BAR with all the radiators boiling hot 🙂. Im going to have a go at fitting a new PRV. Does this procedure sound okay- bleed the radiators so there's no air in the system, screw down auto air vent, drain boiler with the PRV, fit new PRV, then re- pressurise to 1 1/4 BAR? Thanks.