The controller has to know which zone is calling for heat, because the controller controls the boiler relay. It doesn't mean the controller decides when to ask for heat (the valve decides that), but the controlelr should certainly know which zone is asking for heat.
Ahh - I wondered whether a bound TRV and a bound boiler relay could talk to each other directly.
I suppose it would be easy to find out - pull the batteries from the controller and see if things continue to operate!
Even if the TRVs are calling for heat via the controller it could just be as a mesh type network (relaying commands without actually looking at them).
Who know.... Come on @Rameses, give us the details!
P.
No, AFAIK you cannot do this, they are bound to the controller (or another central device e.g. a smart thermostat) but not to each other.Originally Posted by paulockenden
If the batteries are removed then comms with the valves will be lost and the system ceases to work (except for the BDR91 if the Failsafe mode is enabled). The valves also go into a fallback mode where they check for updates progressively less frequently and may take up to 24 hours to recover unless re-initialised manually.
Anyway the setpoints would not change according to the schedule as the time/temperature info is definitely stored in the controller.
AFAIK it's a radial network. If it were a mesh then intemediate nodes could act as range extenders by relaying messages, this does not happen in practice (but the facility has been requested by several people).
Last edited by sharpener; 22nd April 2015 at 12:25 PM.
The BDR91 (and the HC60NG before it) have 4 address slots which are used to register the communication links between paired devices, so that is why the Evo Touch collates the demannds from the HR92 zones and then sends a single demand to the BDR (thereby using one of the 4 address slots in the BDR). This is the same adressing method that has been used for all devices that have used the HR80 and HR92 (so Hometronic, CM Zone etc).Ahh - I wondered whether a bound TRV and a bound boiler relay could talk to each other directly.
I suppose it would be easy to find out - pull the batteries from the controller and see if things continue to operate!
Even if the TRVs are calling for heat via the controller it could just be as a mesh type network (relaying commands without actually looking at them).
Who know.... Come on @Rameses, give us the details!
P.
The system still uses a distriubuted intelligence model, where the control processing is genreally handled locally by that device, using comms between modules to pass relevent data (setpoint data from the main controlled, room sensor values from remote sensors, heat demand back to main controller or BDR directly in the case of HCC80R Manifold Controllers for example). That is how the system can then utilise the various failure modes to try and keep some basic form of operaion if one or more communication links drop out for any length of time (which varies depending on which device is in failure mode and what type of comms failure has occurrred).
Sensible Heat
SensibleHeat.co.uk
So going back to my original point, is the controller just sending the TRV a setpoint, or as @G4RHL says, is there more to it than that?
P.
It at least also sends wether to allow local control and wether to enable the open-window feature..
And of course, also the temperature reported by the zone's temperature sensor.
Evohome is the control hub, the HR92 are semi autonomous but can't work without the Evohome
I work for Resideo, posts are personal and my own views.
So after reading through this long thread, would everyone recommend EvoHome s a new system?
I'm testing with a new BDR91 right now... Afterwards (in a week or 2), I will be able to comment on that.
I'm very pleased with my setup (DHW+14 rads).
Honeywell sells it on a "look how much you'll save" basis, but for me the big plus points are comfort and convenience, rather than financial.
I did have to set it all up properly after the professional installers had left, though...
P.
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