Woke up this morning and the hot water cylinder is leaking up near the top where the immersion enters the tank. I’ve turned off the cold supply to the tank and attempted to drain down tank by opening hot water tap but it only flowed for about 10 seconds before stopping. I assume this is because the cold feed from the bottom of the tank drives the hot water upwards? On the tank itself there are 3 inlets…1 bottom left which I’ve switched off, 1 bottom right which comes from under the floor and the last one is midway up tank (I assume this is the hot supply to the coil which heats the water). Should I shut off anything else or reopen anything in order to drain down the tank?

By turning off the cold feed then you’ve created a vacuum in the tank when running off the hot water. To drain it down then you have to drain the loft cold water tank down too (with the valve you’ve turned off switch back on). Either turn off the house cold water supply or lash up the loft cold tank ball valve with some string/wire so it won’t fill the tank while you’re draining down.

Someone else may have an easier solution 🙂

Ring me bud ill talk you through it. 07849362315.

Morning, yes your right, cold feed from the bottom pushes hot water out of the top. Is there not a drain cock fitted to the bottom of the cylinder?
If not can you disconnect the hot feed out of the top of the cylinder, feed in a hosepipe and syphon the water out?
Failing that, if the emmersion heater is fitted right in the top of the cylinder make sure cold feed is off, drain through hot taps downstairs and then just take the thing out, you will get some water coming out but not too much, just sponge it up as you go.
I’m assuming the gasket around the heater has failed or has someone split the cylinder over tightening it?

Tonup – thanks for the kind offer but I’m in Ireland so will cost an arm and a leg to make the call.

Singlesman – no ones gone near the tank so maybe could be a gasket.

Give us a bell ill talk you through it bud im a plumber.
Its simple 07849362315

Fair enough bud

There’s no evidence of further water coming out so I’m happy until a plumber can come round to fix it. Unless I’ve done harm by creating vacuum?

The gaskets do fail sometimes but quite unusual, before you take anything apart it’s worth carefully checking the pipe work above the cylinder for leaks as this can sometimes run down and pool up around the heater.
There will be an open vent to the storage cistern in the loft so you can’t cause an air lock by turning off the cold supply, but some plumbers do prefer to drain the roof tank as well just incase the gate valve should fail.