Hive 2 wiring advice

This might be a bit of a challenge as I really don't know an awful lot in this field but to cut a long story short I've taken a Hive 2 (with hot water) out to Spain for a new oil fired central heating/hot water (with solar) system. Naturally enough the Spanish plumbers aren't familiar with the Hive 2 and to be honest central heating isn't that common here at all.

I thought I was well prepared to help advise how to wire the Hive 2 when I found this :



Only to find out that the cylinder doesn't have a thermostat, and doesn't have a port to connect one to, so we met a bit of a dead end. We've got the Hive 2 working ok for the central heating which is good.

My question basically is, do you reckon a clamp-on pipe thermostat (eg Siemens Ram 1)
https://www.downloads.siemens.com/d...spx?pos=download&fct=getasset&id1=A6V10424347 correctly placed could be used in lieu of a cylinder thermostat? Might be a silly question but I'd like to go back to the plumber with some conviction.

I can provide more info on the specification of the set-up if it helps.

Cheers and thanks in anticipation

Chris

That stat will be fine, although it is not necessary to get the Hive to work. I assume you do have a Y plan as shown above, with a 3 port mid position valve? And the existing system was working properly before? I assume the solar part looks after itself and is not wired anywhere into the above diagram?

The hive replaces the programmer and wont care if you have a cylinder stat wired or not. If you have no cylinder stat then in the diagram the 3 wires to the cylinder stat disappear, and the wire from terminal 3 of the programmer connects to the terminal with the orange wire from the valve in the wiring centre (terminal 8 in the diagram above) And will still work fine. In this case the temperature of the water will depend on the flow temperature coming from the boiler.

For connecting the Hive you need only look at this part of the diagram:

Noting:
1 - Hot water off
2 - Heating off (not used)
3 - Hot water on
4 - Heating on.

Label the wires and put them in the corresponding terminals of the Hive.
If you have the industry standard backplate on your existing programmer all you do is unclip the old programmer and clip the Hive in it's place, no wiring alternations needed! But from your description this isn't the case. How did you control the hot water before?

Hi Echo.

Many thanks for your quick response. It's a brand new installation. Hot water previously was via a bottled gas heater.

There's a 3 port valve for sure so I assume it's the Y plan as you call it. The solar does "look after itself" as far as I know and isn't wired into anything else.

I hope I can explain this to the plumber ok, in Spanish!

Fingers crossed - I'll keep you posted.

Cheers

Chris

Do check it is a mid position 3 port valve, a 3 port diverter valve looks very similar and will often have the same wire colours, but is wired completely differently.

Aha. I think you might have hit the nail on the head. Just read up the blurb on the 3-port and it is indeed of the "diverter" variety.

It is still do-able?

I have no idea. I would need to know how the system has to operate and what the ports go to. The wiring will be very different to the wiring diagram posted above.

Not sure what you mean by "how the system has to operate and what the ports go to". Is is not just for switching between hot water and heating? I've attached the blurb if that helps shed any light on the matter.

Do you think if they change it to a mid-position 3PV it would sort things out?

Since my last post I've had a chance to read up on the difference between mid position and diverter 3 port valves and am going to suggest that my plumber changes the installed diverter to a mid position as I'd like the option to heat water while the central heating is on and of course to get full value from the Hive 2.

Many thanks for your help Echo.

I don't know how Spanish heating systems operate, there may be a reason for a diverter valve being needed, but over here this will often only allow heating when the hot water cylinder is up to temperature. This can't be the case with your system as there is no cylinder stat. Though can be set up differently. Ask your heating engineer. If it is ok to fit a mid position valve, also add a cylinder stat for better control as you mention in your first post, and carefully follow the wiring in the diagram you posted .

Thanks again for your response Echo, it really has been a great help to me.