1960's house, Potterton Profile boiler 13 years old, mostly original pipework. The central heating pipes are buried in concrete floors downstairs. The expansion tank in the loft has been filling at a steady trickle continuously for several months, but there is no sign of leaks anywhere in the system. This happens even when the heating and hot water is off. I tried tying up the float and the tank half-emptied within a couple of hours.
There are two rads that regularly fill with air - one upstairs, one downstairs, one is directly above the other (coincidence?). There are no other symptoms I'm aware of - the expansion tank never overflows, the indirect h/w cylinder doesn't overflow.
My boiler man reckons as there's nothing coming through the ceiling, it must be a leak somewhere in the pipes in the solid floor that has yet to show itself. He suggests running new pipes dropped from the ceiling to each downstairs rad, and cutting off the original buried pipes completely (at a cost of about £2000 - there are eight rads downstairs).
As well as major cost, there will be quite a lot of upheaval in moving upstairs fitted furniture and carpets and/or making good if holes have to be cut in the ceiling to gain access to the pipework.
I'm reluctant to commit to this work without having some evidence that the leak really is downstairs... I'd be sick as the proverbial if the tank carried on filling afterwards!
Is there anything I can do to try to confirm where the water's going? I've lifted carpets downstairs, especially around the rads that get air in them, but all seems dry as bone.
I thought about pouring some food colouring into the expansion tank to see if it appears anywhere, but apart from that I'm stumped. Any suggestions (apart from moving house
)?
There are two rads that regularly fill with air - one upstairs, one downstairs, one is directly above the other (coincidence?). There are no other symptoms I'm aware of - the expansion tank never overflows, the indirect h/w cylinder doesn't overflow.
My boiler man reckons as there's nothing coming through the ceiling, it must be a leak somewhere in the pipes in the solid floor that has yet to show itself. He suggests running new pipes dropped from the ceiling to each downstairs rad, and cutting off the original buried pipes completely (at a cost of about £2000 - there are eight rads downstairs).
As well as major cost, there will be quite a lot of upheaval in moving upstairs fitted furniture and carpets and/or making good if holes have to be cut in the ceiling to gain access to the pipework.
I'm reluctant to commit to this work without having some evidence that the leak really is downstairs... I'd be sick as the proverbial if the tank carried on filling afterwards!
Is there anything I can do to try to confirm where the water's going? I've lifted carpets downstairs, especially around the rads that get air in them, but all seems dry as bone.
I thought about pouring some food colouring into the expansion tank to see if it appears anywhere, but apart from that I'm stumped. Any suggestions (apart from moving house
)?
