Leak somewhere in ch system

[gblades]

I have a leak somewhere in the central heating system. It started towards the end of last winter and I did the normal things such as checking the over pressure outlet which was dry so I think its the pipework somewhere.

Over the summer the leak practically stopped (dropped about 0.1 bar every few weeks). But on Sunday/Monday it got much worse and would drop from 1.1 down to about 0.4 in about 8 hours.

I did some intestigating today and checked under the kitchen sink floor where the 25mm pipe (or is it 28mm?) goes to a T fitting and then splits to 3* 10mm for each of the downstairs radiators but it all seems dry.
The pipework is 10mm and has a blue plastic sleve over it. Worse is that the floors downstairs are concrete.

Given the amount of water that was leaking I think it would have to be downstirs or in the pipe running up the wall to upstairs (there is a box section where oviously the normal drainage and sewage runs so I guess water pipes are in that aswell).

Any suggestions what can be done to track down the problem?
Maybe isolating the radiators and then disconnecting the pipework under the sink and pressure testing it somehow?

 

[mickyg]

what boiler have you got. first thing is to rule this out. make and model please squire.

 

[petit_pablo]

I have a leak somewhere in the central heating system. It started towards the end of last winter and I did the normal things such as checking the over pressure outlet which was dry so I think its the pipework somewhere.

Over the summer the leak practically stopped (dropped about 0.1 bar every few weeks). But on Sunday/Monday it got much worse and would drop from 1.1 down to about 0.4 in about 8 hours.

I did some intestigating today and checked under the kitchen sink floor where the 25mm pipe (or is it 28mm?) goes to a T fitting and then splits to 3* 10mm for each of the downstairs radiators but it all seems dry.
The pipework is 10mm and has a blue plastic sleve over it. Worse is that the floors downstairs are concrete.

Given the amount of water that was leaking I think it would have to be downstirs or in the pipe running up the wall to upstairs (there is a box section where oviously the normal drainage and sewage runs so I guess water pipes are in that aswell).

Any suggestions what can be done to track down the problem?
Maybe isolating the radiators and then disconnecting the pipework under the sink and pressure testing it somehow?

Is there space to cut in a a full bore valve on both the flow and return for the downstairs rads? If so, you can isolate the downstairs circuit and see what happens with the pressure. If it does stabilise the pressure then possibly repiping the downstairs will be the best solution as it could be anywhere in the floor.

 

[gblades]

Its a worcester 240 fan assisted combi boiler.
Normal pressure is 1.1bar and this goes up to 1.7bar when the heating is on. The over pressure outlet outside is dry and there isnt water leaking inside the boiler.

Yes there should be space to put in a couple of isolating valves. Not particularly easy but should be able to loop the 10mm pipes to get enough space.

 

[gblades]

Here is a photo of the heating pipes as they then go onto the downstairs radiators.

Good suggestion about putting in an isolation valve. I could either put in a couple of 22mm ones or I could put a valve on each of the 10mm pipes.
Any suggestions? If I put it on the 10mm then if a pipe was leaking I could tell which radiator it was and leave it shutdown until I got the pipe rerun.

I am guessing it wont be too difficult. Would need a few loops of 10mm pipe as there isnt space there to insert isolators.

Now I have has a look but cant find 10mm isolators unless I get gas ones (some say can be used for water). But I could also get the much cheper 15mm isolators and use a reducer at each end. Any reason I shouldnt do this?

 

[petit_pablo]

Using a 15mm fitting with 15-10mm reducing olives will be ok.