Hive installation questions

I have just purchased a Hive system to update my CH & HW system. I live in Northern Ireland where there is no British Gas presence, and when I rang their support line to ask about the wiring into my existing system they refused to help, and even advised that they knew of no installation engineers in Northern Ireland!

My system comprises a Baxi Solo boiler, with a separate Megaflow HW tank. The boiler is presently controlled by a Horstmann Centaur C27 Programmer and a Honeywell thermostat. I have opened the programmer and found that it is wired only to terminals 3 & 4. I'm assuming from this that it is a “gravity fed system” even though it is at mains pressure.

The hive installation manual focuses on a four wire connection, but advises that it can be reprogrammed to suit gravity fed systems. However, it is vague about the wiring needs. All it says is - “complete wiring and reprogramme”.

My questions are:

1. The Centaur backplate appears to be compatible with the Hive receiver (barring the wiring issue above). Is this correct?
2. Do I take the existing thermostat out of circuit?
3. Do I need to move any of the thermostat wiring into the backplate to allow the Hive to function correctly?
4. Do I need to do anything at the boiler end.

By the way I was pretty horrified at the quality of the terminations when I saw the backplate! I plan to tidy these up during the work.

I have attached pics of the key elements to help.

I would be very grateful for any help and advice.

Thanks in advance

Brian

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By the look of it you have an S Plan system, using two zone valves. It is not a gravity type control system. Its correct only to have 3 and 4 used, one for heat one for water on.

If the receiver fits onto the back plate, fine, but I’d tidy up the connections first.

You can either wire out the existing room stat at the stat itself, or better still trace it back to the wiring centre and link it out there, that way the old stat can be removed permanently.

Nothing needs doing at the boiler.

Many thanks.