Can someone answer a basic connection question for Nest 3rd Gen thermostat? Google support pathetic

[bryanbdp]

This is a new installation.

My combi boiler has two TT wires, which are internally powered by the combi boiler.

I have installed an external 24vac transformer to power the nest. From what I've read, powering the unit from the TT terminals is not a good idea.

So, how do I attach the 4 wires? One T wire would probably go the W1 for heat, does the other wire go to the common terminal? Then, how to I attach the two external power wires to the Nest without a conflict with the TT wires.

I am incredibly PO'd that there is no professional level documentation available for this product. Good wants you to hire a 3rd party company to install your unit, rather than answer a simple question. If I purchased a Taco or Honeywell product, extensive technical information would be available on there website. Google support is a joke.

[bryanbdp]

I can make it work with a relay but was hoping not to have to use one.

[bryanbdp]

no one? Can a nest technician chime in? Phone support utterly clueless. Script readers...

[NVR]

Did your connection for TT wires as shown in your circuit diagram worked? I used same connection . but the home app still can not recognize the thermostat.