Jasper wrote:

My question(s) firstly, what type of cylinder do I have and are
replacement cylinder easily found? (The property is approximately 15
years old). Is the "extra" tank a header tank as I assume and is it
only feeding the cylinder beneath? Is this really some form of gravity
fed system or is the main cylinder sealed and the hot water supply is
under pressure (the hot water supply presure is poor at the best of
times but all propertiues in the development seem to have this
issue??)

As you suspect, it sounds like you have a combined cylinder and cold
cistern. The cold cistern will be supplying the cylinder with cold water
by gravity. Assuming that this whole lot is not situated in the loft,
then that will also account for the poor hot water pressure.

Like for like replacements are still available, although that won't do
anything for the lack of pressure.

--
Cheers,

John.

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