I need to replace a faulty ball valve in my central heating expansion tank: Problem, The valve that turns off the flow to the expansion tank is stuck solid and will not budge. I tried to turn off the main stopcock but although it turns it is not stopping the flow, any ideas
I had the same problem when I moved into our home a few months ago.
Have you tried the main stopcock in the road?
I contacted the local water authority and explained that the main stopcock was letting water by, even when turned off, they were out the following day to repair it.
That applies to the main stopcock in the road - not the one that may be under the kitchen sink (or at least somewhere inside the property). The pipe from the stopcock in the road through your land, including any fittings on the length, is the householder's responsibility.
as a get you home you could freeze the 15mm/1/2 pipe in the loft fit a service isolator then work to you own time.
Get every thing ready before you freeze up though
hth Tez