I'm trying to work out whether we need a single- or dual-channel controller. Hive's customer support was dire: they wouldn't offer any advice and just said "speak to a qualified central heating installer". Imagine not being able to offer any pre-sales advice!
We have a combi boiler which currently has a dual-timer: one for the central heating and one for the hot water. The hot water is pre-heated in a reservoir in the boiler, hence the reason for being able to time when that pre-heat comes on and off, so it's not wasting fuel keeping the reservoir hot overnight.
Hive say "single-channel for combi; dual channel for conventional boiler with hot water cylinder". Our system sounds as if it has some features of both: it's mostly heat-on-demand but with timed pre-heat of a small reservoir in the boiler.
So, single or dual?