possable leaking pipes

[dreaddan]

HI, thanks by flow & return valves do you mean on the ch system?
If so do you know where they are - the things i thought were islolation valves are drains (which was a shock).

Currently it's pressuraing about 1bar more than the cold temp.
I was thinking that if 1 put 1.5bar back in (0.5bar more than now) it should stay about 2bar but if it goes above 2 then it points to the vessel.

What cols pressure? do you mean cold pressure?

Thanks
Dan

 

[MANDATE]

Cols should read cold (the 's' and 'd' keys are adjacent)
So when you use filling loop, you would set water pressure to 1bar with the system cool and you would expect it rise to 2bar when heating is on.
When boiler stops the pressure would then drop back to 1bar as the water cools. So generally you're looking for a range of 1bar, anything significantly above that points to expansion vessel problem.
(unless the filling loop has been left attached and is letting water pass)
At the bottom of the boiler at the back will be 5 pipes.
There will be 'gas'. Then 'cold water in' which comes out as 'hot water out'.
Then you will have the 'flow' pipe to heating and the 'return' pipe from heating. These will be 22mm pipes each having an 'isolation valve'
It should all be shown in the installation manual.

 

[MANDATE]

This might help. page 17

http://www.hgdheating.co.uk/downloads/SEBoiler/Quattro Manual Pre CVI.pdf

 

[dreaddan]

The manual I have points to them being under the boiler - however the parts I thought were the isolation vales start to leek when turned so I assume there knackered or not isolation values

Pic
http://www.dread.eu.org/thedump/IMG_5799.JPG

edit:
The manual i have is this one
http://www.hgdheating.co.uk/downloads/SEBoiler/Quattro Manual Pre CVI.pdf


Dan

 

[dreaddan]

Thats what i tryed when turning the flow not even 1/8th of a turn water starts to come out of the thread.

And yes the sytem was cold at the time.

 

[MANDATE]

Yes those in your picture are the flow and return isolation valves, must have weeped a little to get verdigre around the threaded parts.
The valve spindle has a 'O' ring which may also have wept a little, can see a little green verdigre.

 

[dreaddan]

k, so as the valve spindle started leaking when i tryed to turn them should i bother to try again or assume there nackered?

edit: by leak i should say has a fine spray jetting out of it.

Thanks

 

[MANDATE]

I think I would be tempted to 1st bleed a radiator so the pressure drops to zero. (this will reduce the leak flow)
2nd Then close the isolation valves.
3rd Up the pressure to say 2bar. If this could be left overnight you would know which side of the valves is the problem.
Pressure holds then no leak on boiler side through expansion vessel or PRV. If pressure drops then problem must be on boiler side,so no point lifting floorboards etc.
Also while the isolation valves are closed you can drain off the water from the boiler. (better to use drain plug if there is one ,otherwise PRV)
Now with the water drained from boiler, this is the ideal position to change the 'schreder valve' (halfords) on the expansion vessel and re charge it to about 10psi or 0.8bar.
This way you will know there is no water behind the diaphragm taking up space that should be 'air'
From what I've read it seems most of these type problems are expansion vessel related.
So closing the valves is good for deciding which side fault lies and in conjunction with opening the PRV its good for re charging vessel correctly

 

[dreaddan]

Thanks I might give it another go tonight.
Im just worryed about the valve leaking permantly/completly given it's leaked allready when turning it.

I did also repressurise the system to 1.5bar when cold and it was running at 2bar hot.

Thanks I appreciate your help
Dan

 

[MANDATE]

Thanks I might give it another go tonight.
Im just worryed about the valve leaking permantly/completly given it's leaked allready when turning it.

I did also repressurise the system to 1.5bar when cold and it was running at 2bar hot.

Thanks I appreciate your help
Dan

At those figures 1.5bar to 2bar I'd be more than happy.
I set cold pressure to 1bar and expect it to rise to 2 bar. but when it goes from 0.9 bar to 2.9 bar which is almost the PRV set blow off pressure, I realise some of the 'air' capacity is lost from ex vessel.

A gradual loss of pressure with system off indicates a leak from
(a) The PRV not seating properly and letting water pass
(b) A 'air' leak from expansion vessel, which reduces both the air pressure and the water pressure as the diaphragm compresses the air and assists its escape path(like slow puncture)
(c) A water leak in the system (usually around valve spindles)
I also think a water leak in system would show itself with wet carpet/ceiling.

 

[dreaddan]

Cheers im pritty sure it's not a leek as there no wet patches or tidemarks on the carpets or cellings. I've pulled up most of the floor bords and got into the loft space wheres there a leg with nothing showing.

I let 0.5bar out of the drain which resulted in just inder a pint of water so that would be showing by now.

None of the rads had any air in either so I've islolated it with 2bar.

So I'll see what happens.
edit: scrap that swmbo decided she was too cold I'll try again tomorrow.
However there was a very small drop in pressure but im not going to read anything into that just yet.

Dan

 

[dreaddan]

Well i isloated it this morning @ 2bar (well slighty above) a few hours later it had dropped by .1 bar.
BG turned up this afternoon and after lots of banging and crashing the guy decided to replace the vent if that doent solve it they'll replace the vessel.

Thanks for the help

Dan

 

[dreaddan]

god dam it!
BG have replaced the auto vent and prv and it's still leaking (though via the prv)!