boiler losing pressure - ch pipes not leaking.

[bright spark]

Leak on exchanger with boiler running maybe. Going down condense drain. Or possibly a leak in cylinder coil.
It would be normal for pressure t drop when cooling especially if exp vessel pressure incorrect

 

[ShaunCorbs]

Your only way isolate boiler from system

And pressure test system to 6 bar if no drop it's the boiler

But I think there will be a drop

 

[darriusdax]

Your only way isolate boiler from system

And pressure test system to 6 bar if no drop it's the boiler

But I think there will be a drop

Interesting... when I pulled the flexi off the condensate and piped it in to a bucket then fired up the system from cold, we got about 2 litres of water in an hour... this seems a hell of a lot. Other information, he has a 50 litre expansion vessel for 2 floors , 21 large radiators in total.
I have been today and stuck a pressure gauge on a towel rail, isolated the flow and return at the boiler, and left the loop heating the hot water cylinder ( the ch thermostat is set to 5, so it should not kick in at all )
I have set it at 2 bar because there are some old compression fittings in the system that I dont want to blow.
So the boiler is being tested at the same time as the ch loop being isolated. I will update on the results.
Thanks for all your help so far guys.

 

[ShaunCorbs]

Interesting... when I pulled the flexi off the condensate and piped it in to a bucket then fired up the system from cold, we got about 2 litres of water in an hour... this seems a hell of a lot. Other information, he has a 50 litre expansion vessel for 2 floors , 21 large radiators in total.
I have been today and stuck a pressure gauge on a towel rail, isolated the flow and return at the boiler, and left the loop heating the hot water cylinder ( the ch thermostat is set to 5, so it should not kick in at all )
I have set it at 2 bar because there are some old compression fittings in the system that I dont want to blow.
So the boiler is being tested at the same time as the ch loop being isolated. I will update on the results.
Thanks for all your help so far guys.

i would say thats about right how much condensate it should produce

 

[Jay Jay]

50l vessel wow that's some size??? Id expect a smaller size vessel as if oversized that will cause issues mate

 

[ShaunCorbs]

50l vessel wow that's some size??? Id expect a smaller size vessel as if oversized that will cause issues mate

its not far off (think around 35-40l) and no it wont

 

[Chuck]

we got about 2 litres of water in an hour... this seems a hell of a lot.

That would correspond to 24kW continuous operation and with a decently low return temperature.

 

[darriusdax]

That would correspond to 24kW continuous operation and with a decently low return temperature.

Yep , the system would have been cold as it had been off and just topped up with cold mains.... So I guess it was trying to circulate and heat roughly 300 litres of cold water up to 25 degrees. Still it was surprising to see water literally spurting out of the condensate pipe,

 

[ShaunCorbs]

When the boiler isn't on does it still drip ?

 

[darriusdax]

When the boiler isn't on does it still drip ?

I will check, obviously I am not there... frustrating, I want to call the client, but its just another job at the end of the day. By the way.. I went down the bathroom fitting route then got in to leak detection... boilers is probably my weakest discipline because i never did gas work, getting great results with sewerin audio equipment on external pipe leaks, and a ferret machine which inflates a small balloon at the head of a long cable - pressure behind lets you know when you go past the leak. We could start a leak detection forum on this site so that I can help the other way instead of you lads bailing me out all the time