Indirect Unvented Cylinder losing pressure on heating side

[theflame69]

Hi Guys,

I fitted a 210l indirect unvented cylinder a few weeks ago. It worked fine for about 2 weeks but no the customer is constantly having to fill up the system through the filling loop every night before they turn the heating on. When they wake up in the morning there is no pressure. It can't be a leak as surely after 5 weeks you would be able to see a leak patch. I changed the expansion vessel aswell just to be sure and it worked fine for 2 days now they are having to top it up again every night. Any ideas?

Cheers

 

[Kip]

Dodgy P.R.V? maybe.

Hows the d.h.w? Could be a split coil maybe? Unlikey but does happen.

 

[wnjswozo]

could be leak on heating circuit,

 

[Puddle]

To have to refill every night and dropping by next morning,the leak should be noticeable,what boiler is on the system

 

[theflame69]

I was told there may be a chance it is a split coil but is there any way i can test this? The boiler just says Optima on it, it's not a combi boiler though.

I really doubt it's a leak surely topping it up everynight over the last few weeks would show signs of a leak. There is only 4 metres added on the system for a new rad but we can see all the pipework and there is no leak.

 

[Puddle]

Well you say it is an unvented cylinder therefore the water each side of the coil will be under pressure so could not loose all pressure for either system,this would be possible if open vented cylinder
check heat exchanger not leaking,but would not think would loose all pressure over night,confused ,firt you say you fitted unvented cylinder ,then you say you just fitted rad ?

imho

 

[theflame69]

I added the radiator about a month before we fitted the unvented cylinder. So the new pipework surely would have shown up a leak as it would have been constantly filled up through the header tank.

 

[quality]

That don`t seem to make sense is if the heating system is sealed it would not have a header tank hence the need for re-pressurizing