Can Hive smart thermostat downstairs be used in conjunction with 'dumb' thermostat upstairs? 24 November 2022 at 3:08PM in In my home (includes DIY) MoneySaving 28 replies 490 views

HelpfulHints99

Hi there. I think this is a simple question and have seen other folk posting about it but I cannot find a definitive answer anywhere.  Hoping someone on here can help. 

I have a standard (non-combi) oil boiler and an 'S plan' heating system. I have separate thermostats for upstairs and downstairs but these are not separate zones on my timer control. The heating and the hot water can be separately selected - but the heating is either on or off. The upstairs and downstairs radiators are then operate based on the temperature set on the two thermostats. But, for example, I can't select only upstairs or downstairs to be on. The heating is either on or off. 

Question 1:

Can fit a new Hive thermostat/receiver to replace the downstairs thermostat and leave the old 'dumb' thermostat to control upstairs? So depending on the temperature it's set to, it may come on when I turn on the heating on using new smart thermostat but can't be selected independently.


Question 2: 

If I install Hive smart TRVs on two upstairs bedrooms, turn off all the other radiators upstairs and set the upstairs thermostat to maximum (so it's calling for heat), could these allow me to control temperature of these two bedrooms independently overnight?

We can't do this at the moment as the upstairs thermostat is on the landing which is a lot warmer than the bedrooms.  The smart TRVs should, I think, allow us to have the rooms individually controlled - my hope is that if they call for heat, the heating will come on and if the upstairs dumb thermostat is set to max, they will then heat up.  So they create two new zones effectively.  

Can the smart and dumb thermostats work together in this way?

Thanks in advance for any wise words.

All the best

J

Bendy_House

In essence, yes.

But, some of what you say doesn't quite make sense, but I think I know what you mean.

You say "I have separate thermostats for upstairs and downstairs but these are not separate zones on my timer control. The upstairs and downstairs radiators are then operated based on the temperature set on the two thermostats. But, for example, I can't select only upstairs or downstairs to be on. The heating is either on or off."

The two comments in bold appear to be mutually exclusive. You say that each house area (upstairs and down) CAN be controlled by their wall stats, but then go on to say you CANNOT select only up or down?

I mean, if you turn the upstairs 'stat down until it's effective 'off' - say at frost setting - then don't the upstairs rads now go cold, whilst the downstairs ones remain hot? You can either control them by their wall stats, or you can not.

Unless what you are actually saying is that the wall stats themselves do not turn the BOILER on and off - the TIMER has to do that? That would make sense.

You ideally need to confirm for us, please: how many motorised valves do you have? Two or three (Surely three - two 'zones' and the hot DHW tank)

Ok, a Hive, as you'll know, does BOTH temps AND times. If you fit a Hive to a system that already has a 'timer' (programmer) on it, then you'll have to do one of two things with that existing timer; one is to leave the existing timer 'CH always on' (24 hrs), or the other is to remove and by-pass it.

So, I suspect what you may be asking is, if I leave the existing programmer 'on 24hrs' so the Hive can do its job downstairs, what happens upstairs? The answer will be, you'll now need to control the upstairs using ONLY the wall stat. Ie, it'll never time 'off', so you'll need to turn the wall stat down for off, and up for on. That isn't a major problem, but it'll mean you'll be running up and down the stairs quite a lot (keeps you warm...), and it won't automatically be warm come bedtime and morn - someone will have to manually do that.

EXCEPT, you now come to your other idea - the Smart TRVs. Will this do the job of the upstairs wall stat? Yes-ish.

These Smart TRVs work in one of two ways. The first is that it's purely prog'd to open to a set temp at a set time, and offski when also prog'd (very easy to set via the App). For this, the boiler would already need to be running, and that zone already supplied with CH. Ie, the upstairs wall stat would have to be 'calling for heat' (turned up) all of the time, but the individual rads would be turned off - and the two Smart rads would then open and close to demand. That will 'work', but is not good, as the boiler would always be told to be 'on' by the upstairs wall stat, tho' it wouldn't be able to shift the heated CH water - it would then 'cycle' on and off until a rad opens.

The second way the Smart valves can work is to not only open and close when programmed to, but to ALSO then tell the boiler to fire up. That's clearly better, but it means that this upstairs zone also needs a Hive stat so it controls the upstairs zone valve. Without this, the Smart rad valves couldn't open and close the upstairs zone valve as it would need to. 

Phew - I hope that makes sense.

So, really, BOTH zones - up and downstairs - needs their own 'Hive'.

What I don't know is whether the Smart rad valves can control the Hive receiver directly, or whether a Hive 'stat is also required to be fitted. If it doesn't need the Hive 'stat, then in theory you could mount a Hive receiver where the upstairs wall stat is (it might even be a straight swap), and then connect your two Smart TRVs to this via the App. Set the Smart TRVs to 'also turn on the boiler' setting, and bob's your auntie - that should give your upstairs fully independent control.

Meanwhile, downstairs, you have two options* - one is to replace the downstairs wall 'stat with a second receiver, and mount a Hive Mini wherever you want, or else replace the wall stat with a 'wired' Hive - the SLT5. In this case you won't need a second receiver. And one Hub should do both zones.

Your existing programmer/timer would just be set to 'on 24 hrs'. 

*Three options - it would make sense to make the downstairs Hive a 'dual channel' type, and also control your DHW. But that would need more wiring at the existing timer or wiring centre.

BUFF

May I suggest that you look at Drayton Wiser as well/instead (or Tado). Some very good deals on atm on Amazon Black Friday.

fenwick458

Question 1, yes it's possible but would need to reconfigure the wiring to the new hive as it currently goes through the timer, the hive just wants a permanent live it has it's own timer
Question 2, might work in theory but there will probably be issues, I don't know if the TRV's would work completely independently of the other hive? why not just buy the wiser kit 3 for £156 and 2 x smart TRV's for another £70, then you will have full control, rather than a bodged up system.

Bendy_House

Ooookkkàaayyyy, Wiser it is :-(

ChasingtheWelshdream

I may be unlucky but I would not recommend Hive. (I know Bendy is very happy with his so it may be simply my misfortune)

I have tonight written a grumpy email to Hive as my Hive mini is disconnecting pretty much every day, despite purchasing a hub signal booster and having full Wi-Fi signal in the rooms with the hub, receiver and thermostat.

I am finding it simply unreliable, and have the same issues if I remove the hub and place it in standalone mode.

As I type, the heating has gone offline for the third time this evening and we are at 14.8 degrees. At one point after resetting everything again, the app was happily telling me everything had full connection and sitting at 21 degrees. (Not a chance). Half an hour later, the heating is chugging away and yet the app and thermostat tell me it is offline. I have put it in stand-alone mode again and am about  to light the wood burner.

Hmpff. Goes to check out Drayton…

Apodemus

ChasingtheWelshdream said:

I am finding it simply unreliable, and have the same issues if I remove the hub and place it in standalone mode.

I'm still in the learning phase with mine and still enjoying the benefits that has brought...but I do find the app is a bit frustrating. 

One of the issues is that (as you say above) it often tells you something different from what is actually going on at the time.  I find that by checking the graph function, you can see whether the app is actually up to date or not.  If not, refreshing it a couple of times until that screen looks right means that the data has updated properly, at which point the controls conform with reality.

ChasingtheWelshdream

Thank you. I often find (like now), the receiver is saying everything is connected (green light), the app says everything is working with full signal, but the thermostat says “nope, no signal here, no heating for you”.

When it works it is easy to use, I just can’t rely on it to actually do so.

Bendy_House

I have to say, mine has been working just fine. It's been a great addition - I can reach for my phone and drop the temp by a degree or so once we're snuggled under t'blanket with two dawgs watching tele - usually enough to turn the heating off for the eve'. Saves numerous hours of heating.

My one Smart TRV - bedroom - works a treat too - gets bedroom warm(ish) for the morn.

ChasingtheWelshdream

I am jealous   

Now my app says offline, the thermostat says no signal and yet the heating has decided to turn on.  

I think it is doing it’s own Two Ronnies mastermind impression. Answering the command given half hour previously.

Tried it on standalone and it still wouldn’t stay connected so back to the app troubleshooting 

Bendy_House

Where did you buy it, CtWD? From Hive or another retailer? Time to return it for a replacement?

I also installed a two-zone system in a village hall, and had some problems setting/connecting it up. I went on 'chat' with Hive, and they talked me through it in real time, and even remotely sorted a Hub issue. I was really impressed.