System pressure

[stevew451]

Being to a system today where on a gloworm ultrapower sxi the ch safety valve was passing vus loosing pressure renewed but on completion noticed the system pressure on was going way up no passing on loop disconnected ,
But the system is very large 5 beds with 5 bathrooms + 7 rads downstairs so tend to think the expansion vessel internally may not be enough to take up system expansion vus lifting the ch safety valve
Any thoughts ??
apart from that system works a OK

 

[SafeGasInstall]

ev try recharge with foot pump if not put new one or just ad new one to the system i think it was for every rad 1l expansion

 

[Billy Bob Bob]

current expansion vessel would be about 8-10 liter,sounds like its knackerd fit a external vessel 12 liter should suffice,cheap in screwfix or toolstation

 

[stevew451]

19 rads on the system like this since installation +pipe
10 litre internal so i think about a 10 -12 as you say