Worcester Greenstar losing pressure

[muggo]

Thanks Terry. Please confirm there are 4 in the photos and I'll do it.

 

[terryplumb]

Yes there are 4 ,but you only need to isolate the flow and return isolators ( far left and far right pipes)

 

[muggo]

Hi Terry. Although perhaps inconclusive, here's what happened when I isolated it for 2 1/2 hours this afternoon.
Boiler pressure dropped from 1.5 bar to 1.3. When opening the valves again (I need my heating on this evening), I heard no rush of water.
I'll give it another go tomorrow for 4 or 5 hours & see what happens. A win for me is the boiler is losing water, hence no apparent leaks. Boiler under warranty.
I'd appreciate your initial thoughts if you have time.
Cheers, Paul

 

[terryplumb]

Was the system cold ,no heating had been on for at least an hour before you did the test ?
You need to test for a much longer period ,overnight preferably.
If water loss is through the boiler itself ,and there is no weeping joints in the boiler,it's either coming out the PRV ,or the condensate pipework ( pin holed heat exchanger).

 

[muggo]

Thanks again, Terry. Heating had been off for 4 hours with only the odd burst for hot water. I'm away on Saturday for 2 nights so I'll repeat the process over 40 hours and report back.

 

[muggo]

Hi Terry. I closed off the extreme right & left valves after pressurising the totally cold system to 1.6bar. I came home after 40 hours to find the boiler pressure at zero and a water drip from the horizontal drain pipe at a joint indicating water had flowed along it. When I opened the valves, I heard no rush of water on either. The boiler is 25 months old & has been serviced.
What's my next move, please?

 

[terryplumb]

Need to see picture of the pipe that's dripping and context of where it comes and goes from / to.

 

[muggo]

Need to see picture of the pipe that's dripping and context of where it comes and goes from / to.

 

[muggo]

Was the system cold ,no heating had been on for at least an hour before you did the test ?
You need to test for a much longer period ,overnight preferably.
If water loss is through the boiler itself ,and there is no weeping joints in the boiler,it's either coming out the PRV ,or the condensate pipework ( pin holed heat exchanger).

Need to see picture of the pipe that's dripping and context of where it comes and goes from / to.

 

[terryplumb]

Thanks for pics. That white pipe is the condensate evacuation pipe. When boiler is in use ,water trickles through that pipe ,and will run to a drain somewhere.
When boiler is not in use, water should not continually run through that pipe, however once boiler is turned off there will still be a residue in the condensate pipe which will trickle through for a short while.
So it's a question of ...is it continually dripping non stop for a long period of time ( hours) after boiler is not in use.
If it does your boilers heat exchanger is perforated.
The leak on the pipe will obviously need sorting as a secondary issue

 

[muggo]

Thanks Terry. Understood. Guess I can pull the pipe apart to check how long it drips for.
Did the isolated boiler dropping from 1.6 bar to zero not tell us anything?

 

[terryplumb]

Thanks Terry. Understood. Guess I can pull the pipe apart to check how long it drips for.
Did the isolated boiler dropping from 1.6 bar to zero not tell us anything?

It is Indicative of a boiler issue ,however it is not conclusive as one of the valves may not fully close (internally) and could mislead us.
You have checked the copper pipe outside, which is the PRV pipework,for any water coming out of it ?
I did ask much earlier and you told us there wasn't. It's worth trying a plastic bag ,sealed over it,to see if any water collects in it .

 

[muggo]

Thanks Terry. I need to find time to shin up a ladder, disconnect the condensate drain pipe when cold & see if there's a small but steady flow. Nothing is coming from the PRV pipework. As I have to repressurise every 6 hours or so, it has to be going somewhere.

 

[terryplumb]

Did you try isolating the boiler?
Can't you disconnect the condensate pipe ,near the boiler where there is a leaking joint ,looks like a black rubber seal ,where the smaller diameter goes into the reducer, does it just push fit in ?

 

[muggo]

Did you try isolating the boiler?
Can't you disconnect the condensate pipe ,near the boiler where there is a leaking joint ,looks like a black rubber seal ,where the smaller diameter goes into the reducer, does it just push fit in ?

Yes, I've already tried that. See about 6 posts back.
I take your point about an internal pipe leak check and will report back next week.
Have a great weekend.