Potterton Powermax with mains water problem

[Simon C]

I’ve been called out to a problem with a Potterton Powermax involved.

The water pressure coming out of every tap dies off after around 30-50 secs.

I took the multi-block off & pressure tested the mains where I have over 4 bar coming in. I changed the multi-block & although I have a slight improvement on initial opening of the taps it dies again.

I do have a strange “flooding” noise coming from the white expansion vessel which I feel is related.

Can any help me out please.

Thank you

 

[Deleted member 120897]

Sounds like you have an unvented cylinde, which req someone who is G3 registered to diagnose and repair.