Adrian C wrote:
tarquinlinbin wrote:

Went to assist a friend last night who had a crisis with a flood
through the ceiling. Found a concealed wc cistern behind a panel. The
water level was too high and was reaching the overflow. Unfortunately
the overflow exited the cistern and then ran uphill so that it exited
through the wall to outside a good 8 inches higher than the cistern!.
Result-the cistern just filled up and overflowed over the top.

Nah... that's not a bodge, just an incomplete job! What the installer
forgot to do was to carefully seal around the lid of the WC with
plumbers caulk. Eventually the 8 inch rise will be overcome....

lol! Now the OP knows the right way to fix it

NT