Intelligent control made easy
ESi Wiring centre is not compatible an its current form. This has been confirmed with ESi and although small bits of retro fitting can work with the relays. The official line to make it work is to cut it out. There are a couple of considerations and one is the ESi cylinder stat needs the legionnaires setting turned off otherwise Hive may not like this
This is of course where we would put the receiver otherwise you are tracing a lot more wires however if the hot water was not there it would be advisable to take this back to the wiring centre
The cylinder stat is usually configured for legionella mode and this needs turned off otherwise it will interfere with new wiring centre. You can see the manual here on how to do this. Cutting the wires to the zone valves etc reveals exact wiring needed for any standard 10 connection block connector and Y-Plan
Cutting the plugs shows exactly the same wires you would expect to find on the motorised valves. The cylinder stat has 4 wires and has just needs worked out
When the programmer calls for Hot Water, a switched live is sent to the ESi controller HW -ON -COM terminal and also to a Normally Open terminal of a 230v AC Relay contact, the common of the relay contact is connected to the motorised valve (Brown Wire).
When the ESi receives a switched live to the HW-ON-COM, the ESi LED illuminates and an internal connection is made and a switched live appears on the HWS N/O terminal, this output is now wired directly to the relay coil, rather than the motorised valve.
The result of this modification is that when the HW programmer calls for heat, the relay will energise and supply the motorised valve with a switched live from the programmer, should the ESI enter legionella mode, the relay will energise or remain energised depending on the programmers time setting, however, if the programmer is not calling for heat, the switched supply to the motorised valve will no longer be present and the valve will close turning off the boiler.
The advantage of this arrangement is that the boiler firing is dependent on the programmers scheduled times set by the user, rather than the ESCTEDE/B doing this at random times.
The main thing to note is that the legionella setting from the ESCTEDE/B will not reset unless the water, reaches and maintains, a temperature of 60 degrees for 1 hour, this means that the programmers time window must be greater than 2 hours making the assumption the tanks contents will reach temperature in the first hour and maintain this in the second hour.
Modified ‘S’ Plan Wiring Schematic to include Relay Control
