"John Rumm" wrote in message

Not really. If you replace it and don't go the combi route, you will need
to replace the hot water storage cylinder as well with a fast recoivery
one to comply with the building regs.

Do you have a link to this requirement please John?
I have seen people advise the use of fast recovery cylinders, but never
stipulated as a requirement for Building Regs!

TIA

Phil