USB on Nest 'E' Heat Link

[sgreenwood1]

I have a nest 'e' (UK) and the heatlink is powered by AA Lithium's which should last 'years'.

The heatlink has a USB port which for 'fun' I decided to plug into a USB 3-pin adapter.

The heatlink can seemingly be powered successfully by this.

Will any longer term damage happen to the heatlink if powered in this way?

I ask because I'll be the leaving the device in a second home in Italy and it would save any issues re battery replacement.

(Previously asked elsewhere in this forum but it didn't get any response as likely not the correct sub section so apologies if you've seen this elsewhere).

 

[ianmcd]

I have a nest 'e' (UK) and the heatlink is powered by AA Lithium's which should last 'years'

The thermostat is powered by batteries not the heatlink it is usb powered

The heatlink has a USB port which for 'fun' I decided to plug into a USB 3-pin adapter.

The heatlink can seemingly be powered successfully by this.

How can a USB storage device power anything ?

 

[sgreenwood1]

The thermostat is powered by batteries not the heatlink it is usb powered

The nest 'e''s thermostat is powered by a USB adapter in the UK (although it does have a small lithium backup battery to cover power outages).

How can a USB storage device power anything ?

The heatlink has a micro USB port and is not a storage device.

It transmits an on / off signal to the boiler.

It is recommended to power this via 2 x AA batteries. This is only the case for the nest 'e' heatlink I believe.

I wondered whether it could be powered by mains permanently without damaging the unit.

I have tested it for a few minutes and whilst it appears to operate okay, I'd not want to damage it.

I wondered whether anyone else has ever tried this.

 

[MJN]

I have tested it for a few minutes and whilst it appears to operate okay, I'd not want to damage it.

I can't imagine it could be damaged as if they are going to stick a USB port on it they must accept that someone might plug the supplied USB power supply or a data cable into it at some point - whether out of curiosity or simply not reading the instructions in all the excitement of unboxing the thing!

Does it seemingly work when plugged in via USB and with the batteries removed though? I mean full functionality (e.g. including relay switching) rather than just seemingly powering up (for the purposes of diagnoses/updates only etc). If so, I'd stick with doing so!

 

[sgreenwood1]

Does it seemingly work when plugged in via USB and with the batteries removed? If so, I'd stick with doing so!

It seems to function perfectly well via USB without batteries.

The top - purely decorative - cover would need to be removed / altered to leave it plugged in permanently but in my scenario (empty house) this wouldn't matter.

 

[ianmcd]

The nest 'e''s thermostat is powered by a USB adapter in the UK (although it does have a small lithium backup battery to cover power outages).



The heatlink has a micro USB port and is not a storage device.

It transmits an on / off signal to the boiler.

It is recommended to power this via 2 x AA batteries. This is only the case for the nest 'e' heatlink I believe.

I wondered whether it could be powered by mains permanently without damaging the unit.

I have tested it for a few minutes and whilst it appears to operate okay, I'd not want to damage it.

I wondered whether anyone else has ever tried this.

You couldnt be more wrong, the heatlink is powered by the usb plug in adaptor, this links via the hub to the nest E thermostat, the nest E thermostat tells the boiler when to come on or go off, put mains voltage into it then come home go to screwfix and get a new setup

 

[sgreenwood1]

You couldnt be more wrong, the heatlink is powered by the usb plug in adaptor, this links via the hub to the nest E thermostat, the nest E thermostat tells the boiler when to come on or go off, put mains voltage into it then come home go to screwfix and get a new setup

Please see attached from the nest pro install guide for the nest ‘e’.

The thermostat is USB powered.

This sends information to the heat link.

The heat link is battery powered.

This is connected to the boiler to which it sends on / off commands.

 

[MJN]

You couldnt be more wrong, the heatlink is powered by the usb plug in adaptor, this links via the hub to the nest E thermostat, the nest E thermostat tells the boiler when to come on or go off, put mains voltage into it then come home go to screwfix and get a new setup

No, you're mixing up your Nests there (easily done - they've got a terribly inconsistent approach to naming, and then there's the added complexity of US models being different to UK/Europe!).

 

[ianmcd]

sorry was answering to two different post , yes you are correct and no you can only power it by batteries the USB port is for diagnostics

 

[RandomGrinch]

Hi,

If it works via the USB, then fine, give it a go!
However, there may be a reason why they want you to use the batteries!

My nest 2nd generation thermostat could be powered from a small USB supply. It also has quite a large built in battery. Useful for power cuts, but it's also better able to supply a sharp burst of current for radio communications etc.

The switching of relays in the nest 'e' heatlink, may also be an event that could stress a small USB PSU, whereas a battery could easily cope with this spike in current draw.

If you do decide to power it via the USB, make sure the PSU can deliver a decent current and the cable is good quality.

Good luck