Nest Gen 3 Install vs Hive Gen 2 Install UK

[wotsit]

Looking for some advice on Nest 3rd Gen and Hive 2nd Gen installation requirements for my current setup, wonder if someone can assist in answering my queries.

I'll start with an explanation of what I have and where I would like to get to and will drop a few photos here too.

I have a Gas fired Worcester Bosh 24Ri boiler and a hot water cylinder, there is a mid position valve controlling the hot water / central heating so must be a Y-plan setup.

I have a British Gas UP2 timer control ( Drayton LP lifestyle or LP722 rebadge I believe ) and WR1 receiver and T4 RF Wireless Thermostat.

The UP2 control is fitted underneath the Boiler in the kitchen, I have supplied a picture of the backplate

The WR1 receiver is upstairs next to the junction box and hot water cylinder.

The T4 RF wireless thermostat is in the hallway ( battery operated )

( The manual for Hive 2nd gen states the Hive receiver can be fitted directly onto the UP2 backplate as its the same config / backplate )

(The nest heat link would require some rewiring )

My concern is that the Hive 2nd gen wiring diagram shows connections for 7 wires including earth, my UP2 backplate only has 6 wires connected and is missing anything in terminal 2 (usually for Heating Off Normally Closed) . My system currently operates fine so am wondering does this wire need to be connected for the Hive 2nd gen receiver ?

Also for the Nest 3rd Gen heatlink, the y-plan wiring diagram shows that the Heating Off NC terminal doesn't need connecting ( matching my backplate and current wiring) but has terminal 2 for heating relay common and terminal 5 for hot water relay common ( can these both be bridged from permanent live as per wiring diagram for nest y-plan)

In both scenarios, would it also be just a matter of disconnecting the cables from the existing WR1 receiver from the junction box. Would the Junction box require any rewiring or modification ?

I am trying to work out whether one system will be simpler to install than the other and also how much it will cost for a pro to install all of this as I believe the Nest Pro installers will assess and quote accordingly and I don't want to be ignorant of whats actually required and be overcharged at all or fed BS to "justify" a hefty install quote.

Thanks for any help and let me know if further details are required for any of this.

 

[Cgas]

Can't speak for installing the NEST but it's a 10 minute job to install hive onto your current setup, if that.

 

[flameport]

The Nest Hive box fits onto the existing UP2 backplate with no rewiring required. It's a 30 second job.
The lack or presence of wires in the backplate is irrelevant - most systems do not use or need all of them. If any were missing or incorrect, your system would not work now.

The Nest Y plan diagram is technically correct but uses non-standard numbering for the terminals, omits a fair amount of wiring and is therefore a confusing mess.

The WR1 thermostat box should be removed. The live and switched live wires to it must be connected together permanently. This can be done at the location of the WR1 box, or preferably at the wiring centre so the cable to the WR1 can be completely disconnected and removed.

 

[wotsit]

Thanks for the info so far Cgas and flameport, I'm starting to think I should go for the Nest 3rd gen, if so from the sounds of what you are saying I could do the install myself if I isolate the system and link switched live and permanent live at the junction box going to the WR1 and decommission the WR1 box completely. As for connecting the Nest 3rd gen heatlink to the UP2 backplate with no rewiring required, does that mean I would not need to connect the Heating and Hot Water Common wires ?

 

[flameport]

What I meant to write was the HIVE fits onto the backplate without any wiring changes.
The Nest can be used but has that non-standard terminal arrangement.

You do not need CH off, that is rarely used.

The Nest common terminals 2 and 5 need to be connected to permanent live - the existing programmer and the Hive unit work in the same way but the common terminals are not accessible, the links to live are internal to the programmer / controller so all you have on those are the 4 switched outputs.

 

[Phill Peck]

With what I've got there I'd go for hive.

I've got hive1. I have hive2 but not got round to swapping it over yet.

Because you currently have a wireless room stat. There won't be any wires to power the nest so you would have to use the 12v power supply cable which looks stupid.

 

[wotsit]

Thanks again flameport, that makes sense now, you've all been Diamond, ill be back hopefully once I get around to ordering and installing to let you all know how it went and whether or not I made the right decision (for me obviously)
Gasservice1985, agree with what you are saying and would most likely be the easier option in my case, but my next challenge is this, behind the wireless room thermostat, there used to be an old wired thermostat from a previous gloworm boiler that was in the property, I told the chap doing the install of my new boiler back then to keep the wiring to the thermostat in place ( 4 colored wires), in case I ever needed it in future ( its all concealed and goes to either the junction box ( decommissioned near it ) or above the boiler in a boxed in cavity.) I am hoping if I can locate the other end of this and use a tester to ensure it is the correct wiring, I can wire it into the Nest heatlink and as I believe this wiring not only provides the DC power to the Nest thermostat but uses it to communicate to it too.

 

[Phill Peck]

I haven't seen the nest 3 yet but with previous models the wires were for power only communications were done wirelessly.
@dean7445 will be able to confirm that
If the wires are there that would be an option for the power supply. But remember these need to go to the heat link for 12v supply so could effect where you locate that.

 

[Dean744PiN5]

I haven't seen the nest 3 yet but with previous models the wires were for power only communications were done wirelessly.
@dean7445 will be able to confirm that

Yes still just power only on t1 and t2 it does nothing to improve communication.

 

[wotsit]

OK thanks, I have opted to go for the Nest 3rd gen, should be receiving it sometime this week, will post back with success/failure stories

 

[HootingOwl]

Odd way to approach a choice of product - nest is a learning thermostat whilst hive requires schedules to be set. I have hive 2 and it is superb. Nest would not cope with my erratic and changing needs. Go with what fits your requirements rather than which is easiest to fit.

 

[wotsit]

I was still researching choice of product when I opened up this subject and wanted to know complexities of installation in case that became a deciding factor at all. My tendency was toward the Nest at start of opening the thread as I wanted a learning thermostat but was open to going for the Hive if the reviews for Nest didn't live up to expectation. Being able to control the heating and water remotely was a priority, learning and AI was a second and then feasibility of install. I have opted to go for the Nest even though the Hive would be much more simpler and easier to install in my current setup. I opened this thread solely for resolving my questions about the third criteria.

 

[HootingOwl]

Thanks for clarification, OP. Much appreciated..