Very high pressure on combi-boiler - Sime format 80C

[TLM1984]

Hi there,

I have been looking around this forum but have been unable to fine a solution to this problem.

I have a combi-boiler (Sime format 80C) which was running at very low pressure. So I opened the valve and managed to increase the pressure to around 1, however the pressure kept rising and is now off the scale at over 4. When the system calls for hot water the pressure falls slightly but increases again when not in use. I have tried removing water from the radiators but this hasn't helped. I can't see any other valves coming from the boiler. It was leaking all last night but now seems to have stopped, was this some sort of overflow?

Thanks in advance,

James

 

[LUNAT]

HI


remove filling loop (if fitted) this might be letting water through.
remove excess water from the radiator drain valve.keep about 1.5bar