"HLAH" wrote in message
...
I am on the point of deciding on a new hot water cylinder and I am now
wondering about getting a "Superduty" cylinder - a cylinder with instead of
a primary coil of one tube, a cylinder having a coil with four smaller
tubes and hence greater surface area to transfer heat. Now the idea is to
improve efficiency by reducing cycling and also reducing the temperature of
the return flow and promote condensing.

" The installation of a Superduty will reduce boiler
operating times and cycling periods resulting in
savings of up to 40% compared with systems using conventional indirect
cylinders."

40% is I am sure BS but is a decent efficiency saving likely?

40% is about right. Check if the figures were pre-Part L. If pre-Part L,
then 40% is right. Then it will be about 33% compared to a Part L. You can
also downsize the cylinder too.

And before anyone suggests it - no I f***ing well do not want a combi.

You should consider a combi first. They make some fabulous models now.