"Roger Mills" wrote in
:


As Christian says, S-Plan is much simpler to understand and also
provides volt-free contacts - with the valve motor drive and
boiler/pump switching being totally isolated from each other. However,
if your boiler controls the pump in order to provide pump-overrun,
you're more likely to need a by-pass valve on an S-Plan system.

Given a free choice (which I don't have because I inherited a Y-Plan
system!) I'd go for S-Plan every time. Yes I could (and still may!)
convert it.

Go for it - I did mine a couple of years ago, never regretted it, if only
for the reason I know what's going on.

All you need is enough room - my airing cupboard was tight!, and it's easy

mike