We have a an old solid fuel heating system (which works well and
cheaply too), but the hot water cylinder has corroded and is now
leaking.

The plumber who came to look at it said we needed a 'specially made'
cylinder for solid fuel heating and was going to order one but he's
been rushed into hospital.

I think I could do this job myself if all I had to do was disconnect
it and reconnect the new cylinder....but I suspect the connections are
old BSP fittings rather than metric which might complicate things a
bit.

Suggestions for a supplier would be helpful, and am I likely to be
able to get a cylinder with suitable threads on the connections ?

TIA