Yes you cannot have a single valve bdr91 for CH only. The only single valve setup is for HW. Daft, i know.
I have just found this in another thread:
I guess the controllers have changed slightly - if I go into "system devices" there is no option for sundial valves, there is only "Boiler Control" and "Stored Hot Water". As above, I cannot activate the hot water option as I don't have the hot water kit.Originally Posted by The EVOHOME Shop
So I guess it's back to the post just one above - either I buy the hot water kit, or try my luck with setting the BDR91 up as Boiler Control?
In your situation because you have a separate timer for hot water that powers your hot water valve and evohome will only be controlling heating you should configure your existing BDR91 that is wired to your heating zone valve as BOILER CONTROL.
Your heating zone valve will already be wired to fire the boiler using its limit switch.
Set stored hot water to disabled if you had tried to configure that in the evohome settings.
Before you try to bind the boiler control relay you MUST clear any previous bindings on the BDR91.
To do this you hold down the button on the relay until it flashes slowly then keep holding it until it flashes quickly which takes at least 15 seconds. Then release the button.
A quick flash indicates the relay is unbound. Now hold it down again until it reverts to a slow flash then release - this indicates that it is waiting for a binding signal.
Go into the evotouch configuration and bind it under boiler control. Personally I don't use the guided config at all I just go directly into the settings.
The light on the relay will go out when the binding is successful.
You should now find that when you turn up your HR 92's the relay green light should come on and open your heating zone valve and after about 15 seconds the boiler should fire.
Last edited by DBMandrake; 3rd November 2016 at 06:58 PM.
Aha! Many thanks for confirming. So in my case with the single BDR91 I would now set this up as Boiler Control even though it's connected to the CH valve?
Fabulous, thank you.
Yes that's correct.
Like I said before, use boiler demand relay to control your ch zone valve. Yes Honeywell did remove the Sundial configuration in the wifi controllers.
I've been through this journey and today finally taken a new turn. I unbound the ch bdr91, put the valve in the manual open lock position and rebound my system as a single HW valve configuration with a boiler demand relay (opentherm in my instance).
FYI
If you want your CH zone valve to remain open whenever the system is running ("bypassed") you should wire it to the pump power feed - the manual fill position on many zone valves including the ubiquitous Honeywell V4043 that I use opens the valve less than half way which causes quite a flow restriction when the system is operating.
The manual latch position is only intended for filling and draining not for normal operation.
Last edited by DBMandrake; 3rd November 2016 at 07:15 PM.
I'm finally making progress and have the first two HR92s installed. One thing that I have noted is that it takes a long time (~1 minute) for the controller to operate the BDR91. If for example I switch all heating to "OFF" from the user interfae, the BDR91 only clicks off after a minute.
If I turn the heating back on, it equally takes around 1 minute for the BDR91 to turn on. Is this to be expected?
Interesting and very useful. So looks like a rewiring is needed or a normally open head. Wiring from the pump is a bit difficult for me because the pump is wired directly from the boiler and not my wiring box. But will look into this. Or i could just go back to my S plan configuration. Trouble is that I witnessed several instances where the boiler fired up under the direction of the OT bridge, with no zone valve open. I didn't like all the heat simply cycling through my bypass valve.
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