The central heating overflow tank has been overflowing and disturbing me at night in these high winds where the water can be blown onto the ensuite shower window and window sill. I ordered a new ball valve up last week and fitted it yesterday. As the house is 41 years old and this is the first time it has been replaced I thought it might be awkward to do, but it all went very smoothly. Turned the water back on checked to make sure there were no leaks from the tank joints or adjacent cold water tank, another job, jobbed.
So I thought.
During the night when I went to the toilet I stepped on a wet bit of carpet and found water running down the wall and on the inside of the builtin wardrobe door frame. Put a bucket underneath to catch the water, went up into the loft checked all the joints, that the expansion tank and main cold tank were dry and couldn't see any other leaks, with the raised boards the tanks are on being bone dry, so I left it until this morning.
Again checked everything and then went to the awkward to reach part where all the pipes go under the floor to the airing cupboard. I could then feel wet rockwool insulation, so pulled this away and could see water dripping from the main outlet pipe from the main cold water tank. Traced this along with my hand and couldn't find a leak but did notice some corrosion on a pipe resting on this pipe. Run my finger along the corrosion felt a lump of pipe fall away and saw a big jet of water. Rushed down starts turned the cold water off grabbed a bucket and a bailer, turn on the cloakroom washbasin taps and bathroom taps as I went upstairs rapidly, confirmed my bedroom now had an unplanned waterfall feature through the ceiling and got back into the attic with my bucket and bailer rapidly. Traced the leaking pipe back and found it was the central heating internal expansion overflow pipe. The expansion tank was still about half full, so I was able to bail about 2/3 of a bucket of water out of it.
Where the pipe is so awkward to get to I decided to cut it several inches below the leak and replace the section of pipe. On inspection the pipe has a double fatigue fracture in it with further metal corrosion problems around what was a 7x5mm hole.
, This fracture could have let go at anytime, so it could have been much worse if that had happened during the night or when I wasn't at home.
I've used a soldered joint for joining the new top section to the existing pipe as I could do that in my garage and a compression joint for the other one as it saved me partially draining the central heating system and also because the joint is in the vicinity of the plastic cold water tank, plastic overflow pipe, and a couple of roof joists. Water back on, the pipe is dry as a bone, so just got to wait for the ceilings and carpets to dry and I will then replace, re-artex and repaint as necessary.
The corrosion on the pipe suggests it has been weeping slightly for sometime and me disturbing it, replacing the ball valve, making the leak worse.
