Adding boiler control

[Tregrill]

My Evohome setup is an S Plan system with Hot Water.
So 3 zone valves each operated by a wireless thermostat via relay boxes and the Controller.
No individual wireless TRVs, they didn't work reliably in our old stone building.

Is it possible to add a boiler relay to control it and would that offer any benefit in energy reduction?

[Richard]

Yes you would gain some benefit, as the BDR91 acting as the boiler relay would look at all the demands on the evohome system and operate the boiler accordingly. Important to disconnect the switch lives from the zone valves then though, as you don't want double demands, if you know what I mean.

[Tregrill]

Thanks for the reply, yes I understand the 'duplication' comment.
Is there a wiring schematic for this kind of setup, or even a description of what does what when and why?

Looking and listening to my current setup the boiler fires every 20 mins, presumably because of the Evo's 3 cycles/h setting, but it appears to do this even when there is no Room Sensor demand?
That seems odd and on mild days wasteful.

[Richard]

Thanks for the reply, yes I understand the 'duplication' comment.
Is there a wiring schematic for this kind of setup, or even a description of what does what when and why?

Looking and listening to my current setup the boiler fires every 20 mins, presumably because of the Evo's 3 cycles/h setting, but it appears to do this even when there is no Room Sensor demand?
That seems odd and on mild days wasteful.

evohome works on 4 minute RF cycle windows. Sounds like you might have some RF comms issues going on.