In message , mark
writes
In message , Andy Hall
writes

One comment that I would make is that if you are going to go for a
large cylinder and 35kW boiler, do make sure that the cylinder is a
fast recovery type - not just a part L1 model. Otherwise you will
find that during HW recovery, the boiler may well modulate down to
half to 2/3 output if the heat isn't transferred fast enough. Most of
the major manufacturers have these - e.g. Albion cylinders. etc.


RMC Ultrasteel; I believe they are fast recovery.



OK so no opinions on the boiler then

More food for thought.
rcm say that the cylinder will reheat in 28 minutes given 21kw of input.
My calculations indicate I need about 14kw, sedbuk site says 22kw (!!!)
I plan to have a y plan type diverter and I'd put up with the odd
occasion that I'd need the cylinder re heated from scratch for 28
minutes.

Does this mean I could go for a smaller boiler?
I could use a 622e as this pumps out 22.4 kw or is this too small a
margin?


--
Mark Roberts