Hive multi zone installation

Discussion in 'Electricians' Talk' started by johnny27, Feb 14, 2020 at 7:24 PM.

  1. johnny27

    johnny27 New Member

    Hi all,
    I'm trying to install a 2nd hive receiver upstairs to control upstairs heating. I have a single wire only behind my old thermostat. There is 230v on this wire. Do I need permanent live and neutral to power my receiver. I attached a picture.

    Thanks in advance
     

    Attached Files:

  2. peter palmer

    peter palmer Well-Known Member

    I'm no expert on hive setups but I would say you are best putting the receiver at the wiring centre and disconnecting that thermostat wiring from there. the wire you have is only a twin wire with live supply and switched live out, you would need at least 3 wires to put the receiver where the old thermostat was.

    Could you not have wired the two heating zones together and only use one hive? seems a bit much having upstairs and downstairs heating on different zones unless its a really big house, I know its a building reg to do this for new build houses but once you are in then you can do what you want.
     
  3. johnny27

    johnny27 New Member

    Well i have the hive controlling the whole house for the last 2 years but decided to buy a 2nd thermostat with the baby coming so i could control upstairs more accurately.
     

    Attached Files:

  4. MGW

    MGW Well-Known Member

    As far as am am aware only Nest e has a battery powered reciver
     
  5. MGW

    MGW Well-Known Member

    Hive has heat on demand function with their TRV heads so should be no need for 2 zones only you have a zone for every room.
     
  6. johnny27

    johnny27 New Member

    call me crazy here, i am no expert but could i link 3 to neutral, 2 to live, and then link 3 to 3 on the hive drawings
     

    Attached Files:

  7. johnny27

    johnny27 New Member

    No actually if its off downstairs, there is no power upstairs
     
  8. peter palmer

    peter palmer Well-Known Member

    I'm not sure what you are trying to achieve actually, have you got the plumbing in place to control upstairs and downstairs radiators separately? you would have zone valves in the cylinder cupboard if so, 1 for down heating, 1 for up heating and another for hot water. Are you saying you've had a single hive operating the two heating zone valves together and you now want to split them up. Did you originally have 2 thermostats before you fitted the first hive?

    Just to add, a Hive replaces the room thermostat that is true but the receiver needs wiring to the wiring centre or boiler, not where the thermostat is located.
     
  9. johnny27

    johnny27 New Member

    Ok sorry for the confusion, my original setup was 2 Robus thermostats with one for upstairs and one for downstairs. I installed the hive and put the hive thermostat downstairs where the first robus was and just linked the wire behind it so its permanently on. The robus upstairs is still in place where its just acting as a switch at the moment that i can switch on and off. I want to be able to control this switch using my new hive receiver.
     
  10. peter palmer

    peter palmer Well-Known Member

    Still doesn't really make sense, what is it switching, sounds like its wired wrong to me, upstairs and downstairs should be totally independent of each other. Maybe a picture of the controls in the cylinder cupboard if there is one.
     
  11. johnny27

    johnny27 New Member

    The picture in my 2nd post is the one from upstairs. When i turn the old thermostat is clicks and the heating upstairs turns on. Im not sure what you mean by the cylinders cupboard.
     
  12. peter palmer

    peter palmer Well-Known Member

    Ok I'll start from the beginning, I presume you have a gas supply and a gas boiler, this boiler heats the radiators up when you switch the thermostats on but where does the hot water come from? Does the boiler fire up every time you open a tap as in a combi boiler or is there a store of hot water in a tank somewhere heated up by the boiler.

    I'm trying to work out if there is a wiring centre with valves and what not that you need to alter the wiring to.

    It can be quite complicated to do so can I ask how did you fit the first hive.
     
  13. Mike83

    Mike83 Well-Known Member

    The receiver can’t go at the stats location.
    What actually powers the upstairs stat? Is it a programmer?
     
  14. MGW

    MGW Well-Known Member

    With a non modulating boiler the programmer can switch supply to thermostat/s, which in turn switches supply to the motorised valve/s which in turn switches on the boiler and pump.

    But with a modulating boiler the on/off thermostat does not control room temperature, its job is to stop the boiler cycling in warm weather, the temperature control is done by the thermostatic radiator valve (TRV) or a modulating thermostat, so when split into zones it is OK to have a programmer switch the valves on/off but not really a good idea to have a thermostat connected to the zone valve as this would likely upset the algorithms built into the boiler to control its output, although I have seen many wired the same as non modulating.

    The modulating thermostat some times are manufacturer specific, and some times use OpenTherm, and the manufacturers are not very good at saying exactly how their boilers work, so Hive came up with an idea to allow one thermostat to work with many boilers, so they used a different method to control what the house requires.

    So last year they brought out their own TRV head, it has not been around that long so not that many reports on how well it works, but it does not matter where the wall thermostat is mounted as it only switches off when no TRV is calling for heat, so in theory although clearly not some thing you would do in practice it could be mounted in the airing cupboard, as even when the target is below the current temperature it will still turn on when a Hive TRV head says the temperature where it is mounted has not reached target.

    So the motorised valves can have the heads removed and locked open, as they are no longer required, the wall thermostat down stairs will still switch the boiler on if a TRV upstairs says an upstairs room is too cold.

    Since the Hive TRV head is expensive you can select what rooms have Hive's own heads, which can fire up the boiler as well as limit room temperature, and which rooms have more basic TRV heads which can be programmable just like Hive, but only stop a room heating, they can't fire the boiler up.

    I am using Nest not Hive but I have 4 TRV heads which should talk to Nest, and 5 TRV heads which are just electronic programmable but don't connect to wall thermostat for that I use eQ-3 eqiva heads which can be picked up for £10 each.

    So you only need one Hive wall thermostat, and you can get rid of the motorised valves as once you fit programmable TRV heads be it Hive or eQ-3 you don't need them, with my set up I can have upstairs rooms designated as Office, Craft room, bedroom1, and bedroom2 all running a different schedule, also down stairs I don't heat the dinning room until 4 pm as don't use for breakfast.

    Every time a boiler turns off any heat in the boiler is lost through the flue, so with a modulating boiler we want it to modulate not turn off, only when it is fully modulated do we start cycling the boiler, so we should not be using on/off wall thermostats for temperature control, they are only to switch off to stop cycling.
     
  15. johnny27

    johnny27 New Member

    Yes its gas, the original dual Hive receiver is in the utility room where the original programmable controller was. One wire switches on the hot water and one switches on the rads. It was very simple first time. 5 wires, L, N, heating on, water on and GND. I am trying to figure out what actually powers the upstairs stat. When the heating is turned on downstairs i have 230v on pin 2 upstairs and nothing when its off.
     
  16. Mike83

    Mike83 Well-Known Member

    It seems your old programmer was twin channel.
    One channel (HW) turned on the hot water via the cylinder stat.
    The other channel (heating) supplied power to both room stats simultaneously.
    Does the heating on (4) at the currently installed hive only have 1 wire. I’m guessing it does but at the wiring centre it then supplies the 2 stats you currently have.
    You need to locate the wiring centre.
     
  17. peter palmer

    peter palmer Well-Known Member

    So the original programmer livened up two thermostats at the same time and it seems the OP has replaced the programmer with a Hive that does hot water and heating. So when the hive calls for heat it powers the downstairs zone valve via the linked out downstairs thermostat and the zone valve fires the boiler, as well as this when the hive is on it livens up the upstairs thermostat which when turned on opens the upstairs zone valve.

    so even if you could replace the upstairs thermostat with a second Hive it would only work if the downstairs Hive is calling for heat so a pointless excersise, might as well just link the wires in the upstairs stat together.

    If you want independant control of the heating for both up and down then you are going to have to go into the wiring centre, as said there is probably a cupboard upstairs with a big cylinder in it full of water and lots of pipe work, there will be a junction box with lots of wires going into it and its there you need to make the alterations.

    Like this.

    [​IMG]
     
  18. MGW

    MGW Well-Known Member

    There are two basic ways of creating zones, one is to use zone valves, not really that good as either on or off no control of how much heat, and the other is to use thermostatic radiator valves (TRV) which can gradually turn on/off so produce less hysteresis. The standard wax or liquid heads have two major problems, one they don't show °C but *123456 and you have to try and work out what it means, and two they can't be programmed.

    However you have Hive, and the Hive electronic TRV head is set in °C and it can be programmed, and it can also send a demand for heat to the wall thermostat. So there is no need to have two Hive wall thermostats, the Hive TRV heads with the existing wall thermostat will do a better job.

    There is making central heating work, and also making central heating work in an efficient manor, if fitting Hive I would assume you want it to work in an efficient manor, so the TRV head is king. OK there are some odd systems where the TRV head does not work well, but in most cases the TRV head works very well, the radiator produces thermals within the room which means the return air is a very good indication of room temperature, I have not used Hive, I use Energenie and eqiva eQ-3, but I can confirm electronic heads will hold a room to within 1°C of setting.
     

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