External Expansion Vessel

[Gas Man G]

A few questions relating to fitting an external EV on a system where a combi boiler's one has failed and cannot be accessed without removing the entire boiler.

1- Any brands that's recommended or one's that I should avoid?
2- Some EV kits come with a PRV & gauge. Is it necessary to install when the boiler already has it built in?
3- Boiler EV's are normally charged at 0.8 bar but external ones come pre-charged at 1.5 bar. Do I leave it at the pre-charged level?

Thanks for any advice

 

[Roger Welton]

Fit on the return, no need for PRV, gauge, etc. 3/4" female iron to go onto vessel. Air charge needs setting as dictated by the system (table is in domestic heating design guide)