Using Nest Thermostat E

[dal5band]

We just bought and installed Nest e thermostat from Screwfix. This is the worst supported diy unit i have come accross for many years. There is much confusion on the Nest web support. The name Nest E is used in the USA and in the EU for completly different units. The online tech support crosses over from EU to USA videos and literature as you search for answers to basic technical questions. The flood of marketting about the online functionality and Nest app completly scates over basic technical specifications. Here are some of the questions and what we have found or not so far :

1 The UK Nest e comes as two units - The display /thermostat unit. The base unit called the Heat Link.
2 The Heat link base unit connects to the thermostat connections of your ch system. It supports volt free switching upto 240v , 3amp AC.
3 The Heat link base unit is battery powered so can be mounted away from the boiler. It does not need mains power - in fact any mains must be isolated. It just needs two wires to switch heating on/off. How long the two AA lithium batteries will last is unknown. (The version 3 Nest thermostat uses a mains powered base unit and usb powered display/ thermostat.)
4 The Heat link base unit has a temp sensor ( as well as the temp sensor in the display unit). Not clear how you use this temp sensor.
5 The display unit is usb powered. So you connect a usb cable (supp!ied) from a usp power adaptor plugged into a mains socket. Many photos of the desktop Thermostat E fail to mention it needs to be plugged in. Yet it appears to have an internal battery - no information on how long it would last.
6 The system probably uses RF between the two units. It also connects to your wiFi so you can use the app on your smart phone etc. Not clear which unit has the wifi functionality.
7 There is no mention of the range limits between the display thermostat and the heat link base.
8 There is no cable grip in the heat link base unit. So the switching cable or flex may pull out.

We eventually got it installed and working but no thanks to Nest. There are no instructions in the box. You are referred to Nest support which skips between USA and EU videos.
We are exploring the Nest App and programming of the Nest e system.

 

[stem]

The Nest E is a cut down cheaper version of the Nest Gen 3 with some features missing. As you state, it is battery powered and is designed for DIY installation (unlike Gen 3 which can be difficult to DIY) in place of an existing room thermostat controlling a combi boiler, or single heating zone (it doesn't have any control for stored hot water).

Whilst Nest E has been available in the USA for a while, the USA version is 24v only and designed for control of a furnace / air conditioning system that is common over there. Nest have now released a UK version with a simple voltage free on / off contact. But as you have noticed, the support for it in the UK doesn't appear to be in place just yet.

USA Nest E

UK Nest E

 

[Dan Robinson]

But as you have noticed, the support for it in the UK doesn't appear to be in place just yet.

It's just a switch. How much support is needed?

 

[stem]

Judging by the posts on here quite a lot it would seem........

 

[dal5band]

Just a wiring diagram of what the terminals do.

 

[Dan Robinson]

It's a switch. My 10 year old learnt that in year 5 at school.

 

[stem]

The Nest E as well as having the switch terminals 'C' and 'NO' plus Open Therm, also has a terminal marked 'FP'.....anyone know what that's for? I had a look on the Nest UK website, but couldn't find anything about it. So, at the moment I agree with @dal5band.

 

[bernardgreen]

It's a switch. My 10 year old learnt that in year 5 at school.

Maybe just a switch, but whose finger is on the switch.........

 

[hlarry]

Dal5band, can you confirm that the heat link for Nest E (european) works with 240v? I have a Honeywell DT90E thermostat and the live wire is 240v. I just called Google Nest helpline and they said it will not work but I am not sure if they appreciated/still is a difference between the US and European versions of this Heat Link? Cheers. H.

 

[stem]

Nest e (UK Version) is battery powered, so it does not need a 230V mains supply to operate it. This sometimes causes people to incorrectly think it is not suitable for 230V control.

What Nest e does have, are two terminals (labelled C and NO) that are connected to a simple internal on/off switch. When the heating is switched 'on', the switch is closed and the two terminals are electrically connected to each other. When the heating is switched 'off', the switch opens and the terminals are no longer connected together.

As the 'switch' is not electrically connected to anything else, it is described as being 'voltage free' so, if a boiler requiring 24v control is connected to it, it will switch 24v. If a heating system requiring 230V control is connected to it, it will switch 230V.

You can find an example here of someone successfully installing a Nest-e switching 230V.

The american version is designed for their furnaces and unless they have changed things recently, only works with 24v. They are not suitable for UK wet heating systems, so I would be surprised that a UK helpline would get confused between the two versions. Unless it was not a UK helpline you were in contact with.