Correct. I already have a BDR91 wired in to control the CH valve. This is working with the current Honeywell (non-EvoHome) thermostat. Ideally I wouldn't touch the wiring.
HW demand is satisfied through a normal timer clock.
I plan to fit HR92s on all radiators.
Incidentally I have since come across the Wireless Binding Guide
http://getconnected.honeywell.com/en...e%20(v1-0).pdf, which says:
To bind a Wireless Relay Box (BDR91) to a Wi-Fi evohome Controller (ATC928G3000) to control a Sundial valve (hot water or heating)..
On the evohome Controller
1 Press and hold SETTINGS for 5 seconds
2 Press the green tick
3 Press SYSTEM DEVICES
4 Press STORED HOT WATER
5 Press ENABLED
6 Press HOT WATER VALVE BINDING or HEATING VALVE BINDING
Not too sure why this under "stored hot water" but hey - ok.
So when I do this (Stored Hot Water / Enabled) it just says "Hot Water Sensor" - Press BIND button on sensor. I don't have a hot water sensor though? Huh?