Smart Thermostat Question

[simonharries]

Hi

A year or so on from my last question I'm fitting a similar thermostat to my upstairs heating system.

I thought it would be the same wiring as the downstairs but there are only two wires this time! Live & Neutral.

So the one removed was a Honeywell CM907 - has batteries to run the clock etc. so I'm thinking that's the difference - the new one is mains powered.

New one is an AWOW TH113

Thanks!

 

[cross thread]

Your old one is not a live and neutral,it’s a live and a switched live
you need more wires for the new stat

 

[CBW]

you need more wires for the new stat

Or a different/battery operated stat.

 

[ianmcd]

As the others have said you have a live and a switched live , no neutral best to stick with a battery powered one Nest E would work for you

 

[RandomGrinch]

I agree completely with the above, but one last chance - it's unusual to find a cable with just black and grey cores - is there an extra brown core that has been cut off and hidden, in that cable?

Some repurposing of wires would also be required at the wiring centre, it would be much simpler to go with a battery operated stat...

 

[simonharries]

Thanks to all - I thought that was going to be the case. Hopefully I can return the new one.

I wanted to control both areas on one app so will need to change the downstairs one to whatever works for the upstairs arrangement. I'll have a look at the Nest E as suggested.

Cheers!

 

[Johntheo5]

You need something like mine, very basic differential temperature control only (non TPI) but settable, 0.3C to 2.0 differential, gives excellent control.
If you do purchase one that has TPI control as well as differential I would suggest that you get one with the facility to switch off the TPI and with a minimum differential setting of 0.2C to 0.3C.

 

[simonharries]

You need something like mine, very basic differential temperature control only (non TPI) but settable, 0.3C to 2.0 differential, gives excellent control.
If you do purchase one that has TPI control as well as differential I would suggest that you get one with the facility to switch off the TPI and with a minimum differential setting of 0.2C to 0.3C.

Thanks Johntheo5 - I'm after something which can be controlled remotely, via an app.

Great to be able to switch the heating on before we get home - and these days off when we are out or delayed.

 

[Johntheo5]

Very good but dont't forget what I said about the getting one with the option to switch off the TPI and 0.2C/0.3C switching differential to avoid overshoot/undershoot.

 

[ericmark]

Google Nest Mini's allow control of multi items a little like Alexia and the app which goes with it google home allows many items to all be controlled with one app, as to geofencing I have not found it works too well, it may be they are not all the same, Nest only allows home and away temperatures you can't set distance, my TRV heads from Energenie also have geofencing, but not really tried to use it. Can't find it with TP-Link (Kasa) however when I looked to see realised it does things I had not realised, the timing I knew about but the report i did not realise was there. The TRV does not link to the wall thermostat so it can only get the room to temperature if the wall thermostat is causing the boiler to run.

I am told the Drayton Wiser is the best TRV head, it works out how long it takes to heat the room, and links to the wall thermostat so can get the boiler to run.

But unless using fan assisted radiators it simply takes too long to heat a room to wait until due to come home or use geofencing, so I simply use time setting. I have however used phone to turn on AC before returning home, mainly as there is a limited amount of condensate the bottle will hold, so can't leave it on.

The whole idea of the wall thermostat is to stop the boiler cycling when there is a change of set temperature but it is the TRV's that control each room. If wall thermostat and TRV are linked then no need for twin wall thermostats.

I have found the use of phone to alter central heating when away wares off with time, I did to start with, but now just use simple times.