My mains pressure has always been a steady 1.5bar, About a week ago it reduced to about 0.2 The inlet stop cock and pipes make a hissing sound. Pic 1 shows water main A, but there is also an odd thing. If I put my ear to toilet drain downpipe B, there is a clear sound of running water in it. Here’s what I've checked. When the stopcock is off, both sounds remain. When the stopcock in the road is off, both sounds stop. Mains supply in road has been checked by TW and aok. There is nothing going down the toilet drain (condensate, toilet leak etc).
So it's, likely I have a supply leak on my side? I cannot see any external signs of a leak. Is it possible that beneath my slab the water main pipe runs into and through the toilet drain. I'm sure I must have a leak but cannot understand why the running noise is coming from the toilet drain?
