Replacing ESI ESRTP6C with Nest Thermostat (3rd Gen) - Dual Zone

[scooter300]

Hi, thank you for replying. Single channel hive mini X2. Upstairs and downstairs zones. I think I have done it. Please tell me if I haven't though ....
I connected to 0v instead of +v and they now seem to work

 

[RandomGrinch]

I connected to 0v instead of +v and they now seem to work

Yes, as discovered early on in this thread, the ESI switches when RH is connected to 0V.

You have left the +5V disconnected; this shouldn't be a problem, but if you do suffer from any unreliabiliy, the single channel Hive can be set up as follows...

Hive 1: Common to ESI RH
Hive 2: Heating off (NC) to ESI +5V
Hive 3: Heating on (NO) to ESI 0V

This method basically ties both sides of the relay coil to the same potential, meaning it cant turn on accidentally.

For any other readers of this thread - only a single channel Hive can be used; a dual channel Hive would add mains voltage to the (extra) low voltage side of the ESI PCB, with disastrous results!

 

[scooter300]

Brilliant, thank you very much