Nest Wireless 3rd Gen Base Unit (UK Version) T1/T2 Terminal Screw Size

SteveBod — Sun, 05 Mar 2023 11:41:00 GMT

Hi All,

I posted previously on this topic but the thread has been closed so I cant provide an update. I lost one of the T1/T2 terminal screws on my 3rd gen Wireless base unit as per photo below and a kind community member responded with a potential screw size but it wasn't quite right (their screw length was over 13mm whereas mine is much shorter). I've now measured with my calipers and I wanted to provide the actual screw size dimensions and update on my progress with regards to finding a replacement.

The screw I lost is circled below in red, it is one of the 12V connections that links back to the nest wiring unit and provides power to the thermostat itself (using micro usb to power temporarily as you can see in the photo):

Photos of the screw measurements in mm are as follows:

Length without head (shaft length) 4.2mm

Total Length 5.7mm

Shaft diameter 2.3mm

Head diameter 4.6mm

So to summarise:

Total length: 5.7mm
Shaft length: 4.2mm
Shaft diameter: 2.3mm
Head Width: 4.6mm

I headed down to my local Screwfix this morning (Stroud) but they didn't have anything this small in stock. They suggested GR Fasterners in Stonehouse might be able to help but they are only open weekdays (which doesn't work with my commute!).

I instead headed over to ebay and bought the following M2.5 4mm machine screws for 99p (link below). The dimensions don't match exactly but they were the closest I could find. They are due to arrive by Friday and at less than a quid I thought they were worth a shot.

https://www.ebay.co.uk/itm/234484984793?mkcid=16&mkevt=1&mkrid=711-127632-2357-0&ssspo=c2fDk4l7SOu&sssrc=2047675&ssuid=55acNYlMQa-&var=534064481119&widget_ver=artemis&media=COPY

I'll provide an update next weekend with my progress. If they don't fit my options are soldering a small wire with another terminal block on to the T2 connection or replacing the base unit as a whole but these seem to be selling for 50 to 60 quid so will likely go with option 1!

Will update shortly and if anyone has the actual screw specification please do let me know!

Thanks, Steve

Re: Nest Wireless 3rd Gen Base Unit (UK Version) T1/T2 Terminal Screw Size

SteveBod — Sat, 11 Mar 2023 09:53:48 GMT

Morning All!

So the m2.5 X 4mm machine screws arrived on Thursday as scheduled. I have just tried one in the nest base plate terminals and it fits perfectly. Screws in just like the original. So there we have it folks, if you lose one of your T1 or T2 terminal screws you now have the size: m2.5 X 4mm. Thanks all.

topic Nest Wireless 3rd Gen Base Unit (UK Version) T1/T2 Terminal Screw Size in Nest Thermostats

Nest Wireless 3rd Gen Base Unit (UK Version) T1/T2 Terminal Screw Size

Re: Nest Wireless 3rd Gen Base Unit (UK Version) T1/T2 Terminal Screw Size