Hive installation issue - 2 zone system (gas)

23 Jul 2020
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United Kingdom
Hi everyone (y),

I've recently tried self installing Hive heating and hot water (2 channel) on the following system on my 4 years old new build house:

  • Potterton Promax condensing system boiler (garage)
  • Megaflo eco cylinder (upstairs cupboard)
  • Honeywell ST9100c programmer (hot water scheduler)
  • 2x Honeywell CM707 room thermostat (upstairs and downstairs heating zones)

I replaced the ST9100c with the Hive receiver as per the Hive instruction manual and this is synced with the Hive Hub, with all green lights on etc. The Hive app says all is operational and when i turn on the heating / hot water, the green light clicks on, on the Hive receiver, which suggests that is set up ok.

  1. The issue is when I try turning on the hot water, although the Hive receiver clicks on green, nothing happens with the boiler and I get no hot water.
  2. When I try turning on the central heating on the Hive app, the Hive receiver clicks green and the boiler kicks in and feeds hot water into the cylinder and the upstairs / downstairs pipes from the cylinder, however, the radiators do not heat up, as though the valves aren't opening on the upstairs / downstairs pipes linked to cylinder. Hot water does work from the taps and main shower.
I've attached photos of the wiring of the programmer and the thermostats. It seems there is no black wire from the programmer, which may be causing an issue? I also have a wire box next to the cylinder which has wires into in from the 3 valves by the cylinder (hot water, upstairs heating and downstairs heating), though still no black wire.

Any help would be much appreciated! Tried various things and yet to resolve fully. I will eventually be adding a Hive multizone thermostat to control upstairs heating separately, but, one step at a time! :)

Thanks in advance for any help / advice! :)

ST9100c Programmer wiring
ST9100c Programmer wiring.jpg

CM707 Thermostat wiring x2
CM707 Thermostat wiring.jpg
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Your a long way off installing your hive, you have to install two hive receivers, one for ch/dhw and the other for the second ch zone, there will be a wiring centre somewhere on your system and you have to connect the hive receivers to the zone valves, maybe one of the regular posters will do you a diagram but bit much for a diyer.
Thanks for the reply, much appreciated!

The wiring centre is by the cylinder, so sounds like it won’t be replacing the programmer as Hive suggest :(

Hopefully someone will be able to advise on the wiring centre - will post a pic if it helps! Cheers

Your a long way off installing your hive, you have to install two hive receivers, one for ch/dhw and the other for the second ch zone, there will be a wiring centre somewhere on your system and you have to connect the hive receivers to the zone valves, maybe one of the regular posters will do you a diagram but bit much for a diyer.
Pictures always help. As Picasso has said, you'll need to go out and buy a single channel Hive to complete the installation, as this will power your second heating zone. You'll also need a single gang blanking plate
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Thanks again for the replies.

I'm just wanting to add the main 2 channel Hive in initially, adding the multizone later - when they come on sale :)
Effectively I'm just wanting hot water and 1 central heating zone running off the 2 channel Hive, which I thought was possible?

I've added some pics of the wiring center and valve setup by the Megaflo cylinder, if that helps?

Cheers :)

I am sure Hive will work, however I found when fitting Nest Gen 3 the easiest was to rip the whole lot out and start again. In theory if any motorised valve is opened then the boiler should fire up. But why with any house one would want the upper and lower floor on different schedule I still have not worked out, OK can see where an annex needs independent control, but every house I have lived in one room upstairs has been used as an office or craft room, and in the main dinning room and kitchen needs independent control.

So when I am due to arrive home the kitchen is heated first, then dinning room, then living room, if I go upstairs to office I press the boost button and swap from eco to comfort, this simply does no tie into a system where upper and lower floors are independent, and there is no point half doing a job, if a jobs worth doing it is worth doing well.

OK I will admit Nest Gen 3 is not the best system for me, likely Hive would have worked better, however the first question is what do I want, and second question is what can I afford, and you need to decide on the best compromise between the two.

So you can fit one Hive thermostat to open both motorised valves together, and use the TRV heads to select which room is heated, or you can add a second Hive thermostat. Why we use the room thermostat to control DHW I don't know, but I do, and so do many others, but really the DHW does not NEED to be controlled by the wall thermostat, it is just that's a handy place to put the controls.

I like the idea of following Hive, Nest, EvoHome or any other wiring diagram because it saves making an as built diagram for your system.
From what I have read on council websites a TRV forms a zone, and a programmable TRV clearly forms a zone, only with a very cheap installation where not TRV's are fitted would you need other types of zone valve, we find statements like "Building Regulations state that all new and modified wet central heating systems must have a TRV fitted to every radiator (apart from one where the room thermostat or programmable thermostat is installed, typically in the hall)." However with myson fan assisted radiators there is clearly no need for a TRV, it is some ones interpretation of the law, not the law.

It seems the whole trade is full of miss information for example "Standard practice is to leave one radiator without a thermostatic radiator valve installed, and to leave that appliance permanently switched on. If your boiler is fitted with a flow meter – that detects when all of your radiator valves are closed, you can install a TRV on every radiator if you want to." you and I both know the important thing is a by-pass valve, yes a flow meter can replace a by-pass valve, but it is still wrong to give half information.

The law requires that you have zones yes, but it does not state how those zones are formed.

It is the same with the electrical system, we hear all sorts like can't have a socket within one meter of a tap, but all the regulations say is the socket must be suitable for the environment. The is nothing wrong with a socket 2" below the sink powering a waste disposal unit.
If this helps, all my radiators have TRVs except the radiators in the same room as the 2 zone central thermostats (living room and main bedroom).

Effectively, I want to move from 2 zones to 1 zone, which the Hive controls - I'm guessing the wire centre controls the zone valves in the cylinder cupboard currently?

So, if anyone has any ideas how I can get the Hive to work my HW and CH in one zone (rather than the 2 existing zones), that would be much appreciated!

Thanks again for the help (y):)
I will be retaining the second zone on the existing wall thermometer, until I get the multi-zone Hive add on

I'm not sure I fully understand. You need to keep two separate zones, you can't combine them and control both from the Hive you have. Is that what you are trying to do?
The Hive to control HW and Zone 1
Existing Thermostat to control Zone 2.

That as I understand equates to 2 separate zone unless I'm mistaken?

Eventually, the Hive Multizone add on will replace the thermostat controlling Zone 2.

Thanks :)
I would install the Hive receiver in the cylinder cupboard with some 5 core flex, or 2 x 3 core.

The neutral connected to the terminal with all the blue wires in the connection box, and the live to the terminal with the 3 brown and 3 grey wires in it.

Number 3 on the Hive would connect to the last terminal on the right hand side with the brown flex that is in that terminal.

Number 4 on the Hive would connect to the brown wire of the downstairs zone valve whichever it is.

You would also need to disconnect the black wire which was connected to that zone valve and the brown wire that is in the same cable as the black wire you have just disconnected.

Where the honeywell clock is you would need to join the 2 blue wire with a connector and put a separate connector on each of the 2 brown wires. Then put a 1 gang blank plate on the box.

With this the Hive will control your hot water and downstairs heating and the existing thermostat will control the upstairs.

When you get the multi zone for upstairs come back for info on how to wire it up.

If you want the Hive you have now to operate both zones then just put the brown wire from both zone valves together in the connection to terminal 4 from the Hive.

Then disconnect the black wire that was connected to the upstairs zone valve brown wire and the brown wire in the same cable as the black.


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