The Efficient Home Forum

I have an S plan plus setup where as well as radiators there is a single UFH zone controlled by a zone valve. Using Evohome I understand that I will need to control this using an extra BDR91 together with a T87RF2033 room thermostat and set up the UFH as a "zone valve zone".

My question is about wiring for the UFH zone valve. When Evohome activates this zone valve zone, does it also act to fire the boiler (via the boiler control BDR91), or do I still need to connect the orange wire from this zone valve to the boiler as usual?

Similarly, for the zone valve controlling the hot water, when Evohome calls for hot water heat via the water heating BDR91, does Evohome switch on the boiler or do you again depend on the orange wire from this zone valve to connect back to the boiler?

rleather wrote:I have an S plan plus setup where as well as radiators there is a single UFH zone controlled by a zone valve. Using Evohome I understand that I will need to control this using an extra BDR91 together with a T87RF2033 room thermostat and set up the UFH as a "zone valve zone".

My question is about wiring for the UFH zone valve. When Evohome activates this zone valve zone, does it also act to fire the boiler (via the boiler control BDR91), or do I still need to connect the orange wire from this zone valve to the boiler as usual?

Similarly, for the zone valve controlling the hot water, when Evohome calls for hot water heat via the water heating BDR91, does Evohome switch on the boiler or do you again depend on the orange wire from this zone valve to connect back to the boiler?

As per the evohome installation guide, when doing zone valve operations, we don't use the orange wires (nor the grey wire). evohome is unique where it uses one BDR91 (the appliance relay) to do all of evohome's demand switching.