Hive receiver install in place of 3 wire stat??

Discussion in 'Electricians' Talk' started by Reflex88, Nov 30, 2018.


Am I stupid?

  1. Yes, how can you not see you'll burn in a fire ball?

    1 vote(s)
  2. Yes.. though you do raise a good point!

    0 vote(s)
  3. No, You're almost there.. Just need tooooo....

    0 vote(s)
  4. No, You've got that spot on! Good Job!

    0 vote(s)
  1. Reflex88

    Reflex88 New Member


    Looking at a single channel Hive set up (noted as for combi's)..

    Could this be installed in to a Y system, by leaving the existing programmer taking care of water schedule and just replacing the wall stat?

    Popping the existing programmers CH switch to permanent / on, then hooking up the existing 230v thermostats' cables as follows to the HIVE single channel receiver:

    Permanent Live to Live.
    Neutral to Neutral.
    Switched 230v (power out from the stat / call for heat?) to the "Heat On" terminal..

    Would this work, or am i being utterly dumb?

    I hope it's doable, because finding a 230v smart stat setup that doesn't replace the programmer seems a tricky task and there seems no reason for this?

    Many Thanks
  2. Mike83

    Mike83 Well-Known Member

    If using the single channel hive you will need to link live to common.
    Your plan will work though.
  3. Bazza

    Bazza Well-Known Member

    Only that it will stop working when the existing programmer's timer finishes.
    The HIVE should replace the existing programmer, or you'll have to set the programmer to be always on - a waste of space, really.
  4. MGW

    MGW Well-Known Member

    There are many different ways to control central heating, there are two basic functions, one is the control of the room, the other is control of the boiler. So basic idea is if any room needs heat, the boiler needs to run, also if domestic hot water is required the boiler needs to run even if no central heating is required.

    So ideal is for electronic TRV heads to tell a central hub what is required, and for a sensor on the domestic hot water to also tell that central hub when heat is required and the hub in turn either tells the boiler how much heat to generate or if not connected in a way to tell the boiler how much to modulate the output then turn the boiler on/off.

    However this is costly, so often some compromise is used. Hive is such a compromise, it will not modulate the boiler, it can only turn it on or off, personally can't see the point in using such an expensive unit to do such a basic function, however it will often work.

    With an open plan home I expect Hive will work well, but once you add doors to the home, then one has to question if fit for purpose? However Hive will work, and the amount of energy waisted which on/off instead of modulated control will mean is up for debate, however even if anti hysteresis software is not really what is required, it is questionable as to if it saves or wastes energy.

    With a Y plan likely you have no option but to use on/off control, and likely Hive will work as well as any other system, however it has a down side in that it will not interact with the electronic TRV heads.

    I had every intention of fitting Nest, this would follow the eTRV head or the eTRV head to follow Nest, however once stage one was completed i.e. the eTRV heads fitted, I found that Nest was not required.

    So Hive can replace the existing thermostat, however as to if it will improve the system, that's another question.
  5. Mike83

    Mike83 Well-Known Member

    I don’t think hive, nest and all the others improve the system as such.
    They don’t make the boiler more efficient.(maybe a few exeptions)
    They give the end user more control than ever before.
    It’s basically still a programmer and thermostat but in one unit.
    Problems that could arise though are with people now changing the location of the room thermostat.
    I deal with stuff like this all the time but I still don’t have it in my own home.
    I’m more than happy with a normal programmer and room stat.
  6. Bazza

    Bazza Well-Known Member

    Oh dear. It’s always Saturday night when the idiots show themselves.
  7. Reflex88

    Reflex88 New Member

    Ah right, positive noises!

    I was concerned that the load switching capabilities of the smart stat might be a bit low? Manual says it takes a 3a fuse (or should be fed as such) I know that my exisiring stat is 230v, but I wasn't sure if it'd be handling 13amps or summat daft?

    I know it'll in effect by-pass the exisitnng controller, but here's the thing... That lives in the back of a kitchen cupboard so it'd be quite a novilty to put food in the 6in wide gap we've had to leave. Yup.. I've no qualms about setting CH to "on", programming a burst of water twice a day, and forgetting about it.. (if you hadn't guessed, we only recently moved in).

    All I really want to do it turn the heating on and off from my phone. Me and my SO work different shifts so core program hours, whilst possible, are a bit in-efficient.

    The current room stat seems to work well in it's position. It's not a huge house so don't really need smart radiators.

    There's a hole in the market. A wall stat that simply has wifi and an app. No programming elementa, or expansion.. just a simple swap out stat that give you on, off and temp over ya WiFi to ya phone.

    Anyway.. all further thoughts welcome.

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