I am living in a house with an unvened cyclinder in the hot water
system. It is of the Megaflo type.

I would like to turn off the hot water to disconnect an old shower but
cannot find a hot water stop cock only the cold water one in the
kitchen.

Can I just turn off the cold water and allow the cylinder to drain
below the shower level or is that not possible with an unvented
cylinder?

I know these things have "bubbles" in them to allow for expansion but
I do not know whether I can safely partially drain the cylinder
without having to call in a plumber.

I have tried searching the web and have looked at current messages in
this group but have not found a definitive answer yet.

Can anyone help, please?