where is the leak .

cloptrop

Have a heating system with a small sime boiler. Losing pressure from a bar to near zero every few days . Put new expansion vessel in . Blow off looks sound . Thinking of putting a pressure regulating valve on the mains in . Would this be cool . I have access to nearly all the pipework but cant find a leak .

gdavis

coil in cylinder?is old expansion vessel full of water?weep on rad valves?could be anything,u could pressure test system and isolate boiler first then cylinder etc. trial and error

aujopimur

An auto fill valve will only mask the problem, leading to corrosion in the rads and boiler, try a leaker sealer such as "Oxyplus"it might solve your leak.
Ideally you need to locate the leak.

cloptrop

**** lads coil in cylinder its an old one but a good one . Cant believe I didnt think of it . Its only losing about a half a bar every 3 days then sits at a half bar . Do ye reckon leak fixer will sort it if thats the problem or is it one of them one in a hundred times it works job .

gdavis

why dont u disconnect the coil and link the pipes temporarily and see does pressure drop?

cloptrop

gdavis wrote: »

why dont u disconnect the coil and link the pipes temporarily and see does pressure drop?

Yeah ill try that next . I found a small bit of water on a tec tite elbow . Spun the pipe and hit it with a grips . Water seems to have stopped . If that isnt it ill just knock off the ballancing valve on the return and thermostatic valve on the flow and give it a day or two. How much is a standard sized cylinder these days . Havnt bought one in a couple of years .Im a qualified plumber just very out of practice .

cloptrop

Im thinking the fact it sits at just under a half a bar would mean its a leak on the coil . Pretty much because thatd be the pressure in the cylinder . Would I be right .