First thing to do is not to panic to much and take a couple of deep breaths.
Now get all the water turned off at all the stop cocks and make sure that
any water heaters are also switched off.

Now looking at the pictures you've provided links too, I'd say you'd need to
remove the whole top lid off that base tank and clean it all up until it
shines like a new sixpence (sorry, five pence piece, same size). That tank
has been leaking for many a time by the looks of all the corrosion on it, so
it really needs cleaned off before any other judgement can be made on a
remedy.

Get all the water off, especially to the tanks, and then get back to us for
more advice.

If you've already calmed down and done all the water turning off thingies,
then get a shifting spanner....sooorry.....an adjustable spanner and remove
the nut from the elbow fitting that's nearest the door hinges and floor to
the right, and you can use this as a draining point for the tank water if
you put a basin or big pot, bowl or loads of towels under it.

Once you've got a load of water out, then take the spanner and undo the ring
band that holds the pressure vessel on top of the base tank. The bolt is
facing the door, so it's clearly visible and easy to access.

Now go out and buy a big wire brush and some scouring pads and clean the
whole up. Once youve done that, then more than likely you'l be able to
reseal the plate and tank back together no problem with some proper neoprene
sealing rings. But it all has to be shiny clean.


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