Power Connector installed and recognized but does not turn on radiant control valve

[Andrew_Kimpton]

I have a Nest Thermostat and Power connector installed as described in Section 6D of the Pro Installation Guide (there's no C Wire, but I do have a 24 volt AC transformer).

The thermostat recognizes the power connector, and I have none of the common 'power error codes', however when it 'calls for heat' the radiant control valve does not 'open'. 

If I used a multimeter to measure the voltage across the power connector's output (White) R/W lines I see 0 Volts, where I would expect to see 24 volts, in order to open the valve (a regular thermostat, would just 'close' the 24V circuit).

I've tried two nest power connectors and both have the same problem.

[Andrew_Kimpton]

I resolved this problem - and my Nest is now working with my Honeywell Radiant Valves.

Key things I learnt to fix this:

From this post: https://www.googlenestcommunity.com/t5/Nest-Thermostats/Install-Nest-Thermostat-with-Nest-Power-Conn... @dhx227 points out that the jumper isolates the two sides of the power connector so that you can use two *different* 24 VAC transformers. The installation instructions in section 6D do NOT make this clear - and in my case there was no need to remove the jumper (indeed removing it and following the instructions means there's no power to the valves across the white R/W output connectors of the power connector).

This video https://youtu.be/XVs0k1aaza4?si=8c42P-tHL_ui2ycM from HVAC Jersey Mike - and the wiring diagram at the end of the video shows how to wire the power connector with the jumper in place, and how to connect the C, R, W lines from the 'white' side of the power connector to the transformer and the valve (since they can and should all share the same transformer).