Is there anybody out there who can give me advice on how to solve a leak problem?
I have a minute leak from the hot water tank. The tank is the pre-insulated indirect cylinder type. The leak is coming from the junction between the heating coil inlet and the tank itself. The water leaking is fresh water, not from the central heating system which has rust inhibitor in it. When the heating supply to the tank is on, the water evaporates, but when the heating is off a damp patch soon forms. Paper tissue soaks up the water at a rate of about 1 pint per hour. The joint is difficult to access because of the insulation. I would rather not have to take the tank out completely. Any ideas? Jerry firstname.lastname@example.org
Sounds like you have a pinhole leak at the inlet to the indirect water heating coil. These coils are made of copper and usually have cast copper or brass inlet and outlet fittings that are brazed on, and over time pinoles can develop.
I have very rarely resorted to patching such leaks by brazing or soldering (in cases where the owner was too cheap to buy a new coil or the boiler was so out of date and no replacement could be found). The best solution is to pull the coil and replace it with a new one. While you’re at it, make sure you install dielectric fittings where they are needed (if you have copper and ferrous pipe together).