potterton combi 80 pressure problem

[linkyplumb]

Hi to you all
My Nan has a potterton combi 80 boiler,that has been playing up recently.
The problem a few weeks ago was that one minute the pressure was reading 1 bar,and about ten minutes after the boiler was on,it was reading 3 bar.
I checked the exp. vessel ,and there was no water coming out of the schraeder valve,although the vessell was only about 0.5bar,so i re-pressurised it to 1 bar.Also the prv was letting by when the pressure was about 1.5 bar.So i changed the prv and everything seemed to be ok for a week or so.
I went round this morning,checked prv-all ok.
Checked vessell,no water coming out of the valve but it still has this problem of pressure rising from 1 bar to 3 bar in about ten minutes.
Does this mean that the exp. vessell could be shot or could it be something else?
Any help and advice greatly received.
Linkyplumb

 

[twgas]

could be schraeder valve letting pressure out of vessel - pump it up again then put some soapy water on it, if it blows bubbles you need a new bit in the valve

 

[peter the plumber]

if i can remember these have a braided hose going to the exp vessel these get blocked and cause this .i know this is true for the se but can not remeber if it the same with this unit pete

 

[linkyplumb]

cheers for the replies guys.
twgas- I have tried the valve with soapy water,and there is no leakage.

petetheplumber- I will check the braided hose tomorrow when I go round

Regards
Linkyplumb

 

[baxpoti]

but can not remeber if it the same with this unit pete

Yes it is.

 

[linkyplumb]

Thanks for the tip guys
Took off hose today and found it was chocker with black sludge.
cheers
linkyplumb