Why does the pressure in my combi rise by over 1 bar now I have a new pressure vessel

[kay-jay]

Re: Why does the pressure in my combi rise by over 1 bar now I have a new pressure ve

the pressure increase you state for the previous exp vessel when it was working.................
well was it? could it not be that it had been developing a slow leak over a long period of time? therefore leading you to believe that the system should normally increase by 0.4bar when in fact if it was completely sealed like the new one may actually have been 1 bar??

KJ

 

[Bernie2]

Re: Why does the pressure in my combi rise by over 1 bar now I have a new pressure ve

Hmm!

I would tend to try and sort it out as 2.5 bar is very close to the boiler PRV's usually set blow off pressure.

 

[honestinjun]

Re: Why does the pressure in my combi rise by over 1 bar now I have a new pressure ve

Thanks to everyone for their input. To answer some questions, make and model are on the original post and to be precise I set the PV to 0.8 Bar which was in line with the original installers guide (no data came with the replacement PV) and was only about 0.5 Bar above the level it was pre charged to.

My central heating system reminds me of the one in my original primary school (1960's) with lovely looking but notoriously inefficient and temperamental 2 column cast iron radiators. Removing all of the air from the system after working on it takes months of dedication, so while I can say that I have bled the system several times now since replacing the PV, it would be reckless for me to claim this could not still be a factor.

I am going to follow the advice to see how it settles while continuing to bleed the radiators on a regular basis and will come back to this post in a months time and let you know where this gets me to.

Cheers.

 

[kay-jay]

Re: Why does the pressure in my combi rise by over 1 bar now I have a new pressure ve

if air in the system is a problem look at spirotech combination valves wich remove both magnetite and air, or you can just get the air release valve. i saw one in action and it was better than any other standard heating system air release valve

 

[Billy Bob Bob]

Re: Why does the pressure in my combi rise by over 1 bar now I have a new pressure ve

what about checking the basics? your filling loop could be knackered