Central Heating Leak

[rwalters]

Yes, 100% sure. We had it leaking several years ago, BG came, put on a new PRV and had to replace the copper pipe going through the way and it wasn't in the correct position for the new PRV.

 

[ChrisR]

say they cannot do anything until there is evidence of a leak

Nice. SO your repeated filling scales up the boiler then its a scale problem which they don't cover.
Try shutting the heating iso valves with the boiler cold, pressurise to say 2 bar and leave it overnight. If the valves do leak you can show them to BG ! If they don't leak, and the boiler pressure stays up, but then drops as soon as you open one of them, you know the leak is on the pipes.

If you isolate the leak to outside of the boiler and the pipes are covered by your particlar BG cover than I don't see why they shouldn't look for it. Repeated filling damages boilers.
I expect they aren't responsible for "making good" after taking floors up though.

 

[rwalters]

Thanks Chris, I have done as you have said. Switched the central heating off, pressurised the system (1 bar, should I go to 2) and isolated the pipework. I will watch overnight and see if the pressure drops, if it does, then I presume boiler leak somewhere, if it does not, then pipework leak somewhere, right ?

Cheers guys for all your help, you are very helpful.

 

[Agile]

Chris very clearly asked you to pressurise your boiler to 2 Bar and you reply that you have pressurised it to only 1 Bar and then ask him if you should put it up to 2 bar.

Obviously as he asked you to put it to 2 Bar then thats what he wants you to do!

If you dont want to follow Chris's advice because you think he is an eejit then I will ask you to put it to 2 Bar. Does that help?

Tony

 

[ollski]

when an engineer has been onsite to look at other issues

Get a Bg engineer in for this specific issue, all jobs have a time on them and if you throw a big new job into the mix then it's likely to get brushed aside.If you turn the isolation valves off and they leak (though its very unlikely on this one) brace yourself for the possibility of Bg refusing to touch them due to 'customer interference'.

 

[Agile]

He could "forget" to tell BG or he could blame it on an eejit!

 

[ChrisR]

You can always open them again and swear you didn't touch them. Customers are born liars, all of em, it's a well known fact..!!

 

[rwalters]

An update for you guys. I had the CH isolation valves closed all day yesterday and overnight and pressurised the system to 1bar, I know it should have been 2bar, the system has dropped to .5 bar overnight.

I opened the CH isolation valves again this morning, pressure stayed stable at .5 bar so it is obviously a problem within the boiler itself not the pipework, so that is a bit of a relief. I have checked the boiler this morning for any signs of moisture and I cannot see anything, all dry as is the PRV outlet.

 

[chrishutt]

That's proof that there is a leak fault on the boiler, so you can require BG to sort it out. Only problem is that it may take them many visits before they solve it, and someone's got to stay in for each visit.

Since there is little evidence of leakage apart from the pressure drop, I would suspect the expansion vessel, so get BG to check that first. I'm puzzled that the pressure didn't rise slightly when you opened the isolating valves, if the system (external to boiler) pressure had remained at 1 bar. You might also have a minor leak there.

 

[rwalters]

Thanks Chris for your reply, I will pop a call into BG now we have pretty much isolated the cause to the boiler. If it is the expansion vessel at fault, where does the water go to the was used to pressurise the system?

Now you mention it, it is puzzling that the pressure did not rise slightly when the isolation valves were opened again, you would expect it to rise a little bit if as you say, the pipework remained at 1bar.

God, I hate water

 

[ChrisR]

It could just be that the isolating valves are "letting by".
Tell BG about the overheating too.

 

[rwalters]

Thanks ChrisR, do you think the overheating issue is linked or a seperate problem ?

 

[chrishutt]

Good point ChrisR. In the unlikely event of either isolating valve not shutting off 100% then we still wouldn't have proof that it's in the boiler. Perhaps worth doing the test again but at 2.5 bar to try to reveal some sign of the leakage.

Have BG check the main heat exchanger. These can leak and such a leak might well be related to an overheating problem.

 

[rwalters]

I will repeat the test at 2.5bar and see what happens. If the heat exchanger is the unit on the left of the boiler, about the size of half an A4 sheet of paper then that was changed about 9 months ago.

 

[rwalters]

Can I just ask a quick question in case I am not doing this right. The isolation valves have a screwdriver slot in them, which when opened is in the direction of the pipework, I am presuming that I simply turn them to the horizontal so that the slot is across the pipe and not in the direction of it ?