Zone Valves, BDR91s and HR92s

[Rupes]

My heating system is set up with two physical central heating circuits each with a motorised zone valve.

Each circuit has a number of radiators which are individually controlled by HR92s.

The boiler is triggered by one or other of the zone valves.

I have a BDR91 wired to each of the zone valves.

But I can't figure out how (or even if it is possible) to set up the evohome controller so that a number of HR92s switch on one of the BDR91s and other HR92s switch on the other BDR91.

Is this possible - if so how?

[Rupes]

OK - so I think I’ve managed to get this partly working.

The main heating circuit is set up with its BD91 as the Boiler relay and several HR92s as Radiator Zones. This has been working fine for a while.

The second circuit feeds a couple of radiators with HR92s and I have managed to set these up as two separate Zone Valve zones but both linked to the same BD91 that opens the valve for that heating circuit.

It’s not quite perfect as I think the Evohome Controller will be swithing on the zone valve for the main circuit as it is designated as the boiler control. I probably need to set all of the Radiator Zones to Zone Valve type and then set the Boiler Control to None.

[Richard]

My heating system is set up with two physical central heating circuits each with a motorised zone valve.

Each circuit has a number of radiators which are individually controlled by HR92s.

The boiler is triggered by one or other of the zone valves.

I have a BDR91 wired to each of the zone valves.

But I can't figure out how (or even if it is possible) to set up the evohome controller so that a number of HR92s switch on one of the BDR91s and other HR92s switch on the other BDR91.

Is this possible - if so how?

evohome is not designed to operate this way. Page number 46 of the evohome installation guide shows how the system should operate when using HR91 or HR92 on all radiators. As you will see from the image on this page, evohome doesn't have a motorised zone valve on the heating circuit pipework when we have smart TRV's on all radiators.