Having problems pressurising system All aspects of plumbing questions and answers, help, tips and information

[Apex84]

Hi there,

I am having issues pressurising my boiler/system. my boiler was below pressure but I had to replace the external filling loop valve (tap had broken on the old one) I did this, and there are no leaks around it. However, every time I pressurise the system back up to 2 bars it drops down to nothing. I also keep bleeding the radiators as they seem to get loads of air in. Am I not running the filling loop for long enough? what am I doing wrong? I can't find any leaks. Any help would be much appreciated.

[stoneyboy]

Hi apex84,
Presumably you had to partly drain the system to replace the valve. It’s most likely that you have not cleared all the air in your system so just keep filling and bleeding radiators. There is not much point in filling the system beyond the 2 bar pressure because the relief valve will operate.
Regards S