Hard wired boiler thermostat

[PolycomC4]

Howdy,
Just bought into the Evohome system and have been "researching" around the net for an answer after reading an "Amazon" review, and it centred around the Evohome ATF500DWH boiler sensor and primarily the CS92 sensor which is required to monitor and transmit (via a wire to a transmitter) the boiler temperature to the BDR91 module and on to the ATP921 base controller...so many pieces in the puzzle just to get a signal to the controller, or more so many peices to deal with/go wrong or need to purchase and batteries to replace.

My situation is that all the above mentioned "transmitting" items will be located in the same cupboard (>300mm apart) so why need the wireless link to the BDR91 for the boiler temperature ?

The "Amazon" reviewed commented " Note that you can get the "connected" sensor T8674A and BDR91 (or you have one already) for pretty cheap on auction sites (new) but not the CS92"

Anybody know if this true, and which wires would be directly connected to the BDR91for the boiler temperature, Id say the science behind it is viable, any thoughts ?

[Richard]

Honeywell evohome is a wireless system. The CS92A transmits the temperature of the cylinder to the evohome Controller, not the BDR91... Have a read in our help section here - https://theevohomeshop.co.uk/content/8- ... -do-i-need

[PolycomC4]

Ah , makes sense now, you need 2 of the BDR91 to control the position of the Y system, 3 way valve for either 1. DHW or 2. radiator heating as a single BDR91 will not serve the function as it only acts upon a single signal, sooo if you want both DHW and heating at the same time, and the 3 P valve needs to be in the midway position, wouldn't the 2 off BDR910 fit against each other for position or would the controller recognise this scenario and only have one BDR91 as the mater or slave ?
Please correct me if Im wrong ?
Thanks for the info.