stop leak on seal on central Heating hot water tank ?

check out my post
http://www.howtomendit.com/answers.php?id=164446.

But you also need to make sure the zone valves are open. These are the blue/white/silver boxes that sit in the pipework somewhere on the system, they have a wire coming out of them, usually located near the pump,or cylinder but can be under floor boards. To make sure they're open, on the valve, they will be a sort of lever that sticks out of the side of the zone valve, if you're not sure what/where the lever is. watch the valve and get someone to turn the heating/hot water on, on the clock, you'll see the lever move across, once you locate the lever, you need to manually put it into the open position and clip it in behind the lug. dont confuse the lever with the zone valve indicater, depending on whether your'v got 2 zone valves or one, the indicate will have an A and B or a HMW on it, the lever will not. Dont think its a a simple case of getting all the water out, then putting all the water back, draining can cause problems, when I'm repairing a leak, I'll drain a system as a last resort. Where is the leak? you may not need to drain the system. There may be other options. I know its a bit of a long winded reply and I hope this helps. Post a reply if you need any more info.

LTGF
August 2008