Please help..

The water tank is continuously filling... however, Its not overflowing. As a result I have no hot water. A friend has looked at the tank in the attic, and has said that water is continuously entering the tank, and therefore there must be a leek in the pipes. There is no sign of water leakage in the upstairs of the house... not sure about down stairs because it is tiled. The friend sais this is the reason I have no hot water... he thinks that the cold water is going through the hot water tank (red cylinder thing in a upstairs cupboard) too quickly and therefore not heating up.

Does anyone have any advise on whether it is likely to be a leak, or another issue.

Thanks in advance

The tank should have a pressure relief valve. Usually they are near the top of the tank. Yours maybe piped to a drain or outside somewhere. Sometime working the lever on the valve will reseat it, but usually if they are leaking, they may need replaced.

Often the valve starts leaking because you have a backflow preventer and no expansion tank. Any time cold water flows into the tank, the excess from expansion must have someplace to go as it heats. If it can't go back the cold line, it will go out the relief valve. Once open, it may not shut off.

TY, are you talking about a water storage tank in your attic or a hotwater heater?

Thanks to both of you for your quick response.
I have since had a plumber out who has diagnosed the problem.
There was a leak in the pipe work on the ground floor of the house under the kitchen. The plumber has run new piping and disconnected the original pipes. The hot water is now working, and the continuous noise I could hear of the tank filling has stopped... thanks again