Pressure increase?

[Thesub]

Hi all,

This might be really obvious but would appreciate your thoughts. Over the last few weeks I have noticed an increase in pressure on the primary circuit of my Halstead Finest. Reset a week ago and still increasing about half bar/week. I'm assuming that the likely candidate is the filler tap (the loop is still in place). The only other point I can think of where external water could enter the system is the DHW heat exchanger, which I replaced just over a year ago. I think the first action is to remove the filler hose (I still have the cap), but before I do has anyone any alternative ideas?

Many thanks

Steve

 

[Puddle]

No,first things first,it is probably one of the two things you say,so start with removing flexible hose/monitor and go from there

 

[Thesub]

Thanks very much, I'll disconnect the hose when I get a minute.

 

[ajsplumer]

yeh i'd have to say try the hose first its the simplest option, as puddle said start with that and go from there.

 

[mooreofdevizes]

The hose should be disconnected as a safety precaution that's why it has two valves and unions.

 

[Thesub]

Thanks for the further replies.

You raise an interesting point about the hose. I left the thing in place simply for convenience, as whenever I carry out work or maintanance, (quite often with this boiler which has had its share of faults) it saves quite a lot of fiddling about. However, I do like to do things correctly and am intested in what the safety issues would be of leaving it in place?

Also, I am trying to remember whether there is a way of disconnecting the filler hose without draining the primary circuit. Is there somebody out there who can refresh my memory?

Thanks

Steve

 

[dougs.cowan]

The filling hose can be removed without draining the primary circuit, there is a check valve on the heating side to stop the heating circuit emptying.

 

[Thesub]

Thanks very much that's good to know.

 

[Billy Bob Bob]

safety issues with leaving the loop in place are because of water contamination if the double check valve failed, if its not a filling loop passing your looking at expansion vessel if this has gone probably prv as well check the small copper pipe outside the building to see if waters passing through it as you say the plate heat exchanger can cause this but unlikely if only a year old

 

[Thesub]

OK have removed filler hose. No obvious leaks, but will monitor and report back.

The expansion vessel and PRV were mentioned but I cant see any evidence of leaking from the PRV. The pressure rise is gradual over some time and if you monitor pressure from cold the rise is steady and similar to how its always been. So, although keeping an open mind, I'm tending to think heat exchanger if fault persists.

Any further advice much appreciated.

Steve