Wire identification

[NateBD32]

Hi there,

Can anyone help with identifying these wires, and the corresponding letters?

I have a red, black, yellow, white, brown and green wire connected to the current thermostat.
The above wires are slotted into ports 1, 2, 3, 5, 11 and 12 respectively.
The ports have the following letters - L, N, C/D01, H/D02, G, FAN/A02.

What does it all mean, and what letters do I pick from the online guide?
The Nest plate only has 6 ports, and are lettered - Y, C, W, G, R, OB.

Thank you,

Nathan

[Markjosephp]

Hello Nathan,

Welcome to the Google Nest Community Forum. I'd be happy to take a look at this for you.

It appears that you have non-standard thermostat terminals. Proprietary systems are currently incompatible with Nest Thermostats. While we understand the convenience and efficiency that Nest Thermostats offer, it is essential to highlight that integrating them with our systems may result in operational challenges and compromised performance.However, some proprietary systems can be rewired by a pro installer to be compatible.

If you have any questions or concerns, please let me know.

Regards,
Mark