Just bought a 'cold fill only' washing machine and needed a bit of advice of capping the hot water pipe. The pipes have got no turn off valves so have had to turn the house water completely. Bought a 22mm cap from Wickes (like the one in the pic) but this was slightly too big so have returned it. Tried fitting a coke bottle cap and it screws on but water is slightly dripping and imagine it wont hold when i turn the water back on. Wickes only sell 15mm and 22mm, does anyone know where i can buy something smaller or have any other tips?