I have an old, disused, hot water cylinder in a cupboard in my (downstairs) dining room (!) installed by the house's previous owners. It has been isolated from the cold water supply in the roof, and the hot outlet pipes have been capped off in an unknown place, somewhere under the upstairs floorboards. As it is no longer in use, I want to remove the cylinder, but it appears to be still full of water. The cylinder has a drain cock at its base, so I connected a hose and jubilee clip to that, and opened the cock, but nothing comes out, except a few drops of water. I guess this is because the pipes connected to it are sealed off, so no air can get into the system. I tried unscrewing the immersion heater at the top of the cylinder, but because that simply caused water to come out of there because there's still water in the pipes leading from upstairs. Obviously, I want air to enter the system fro the highest point, which will be where the pipes are capped off, but as I mentioned, they are under the upstairs floor. I'd really like to avoid taking up the floors to find the pipes, so can anyone suggest a way of draining the cylinder without getting water everywhere, and without ripping up all my floors to find the ends of the pipes? By the way, the pipes that enter the cylinder are old iron pipes, so I cannot use a self-cutting T-connector to create a side-pipe that I can extend upwards to allow the air in.