Connecting a power connector to a Weil McLain boiler (single zone, No control board)

[JFS]

I have a Weil McLain series 2 boiler with a single zone. There is no control board. There are 5 wires coming out of the Tstat terminal. From left a black wire with a label 'C' not connected to anything, a green wire connected to ground, a blue wire capped on the end, a black wire connected to the red thermostat wire, a black wire which goes into a taped connection with black, blue and red wires coming out. the black goes to the thermostats white wire and the red and blue both have caps at the end. So my question is how do I wire the power connector?

Thank You

[JuanCH]

Hi JFS,

Thanks for reaching out to the community! I understand you have a Weil McLain Series 2 single-zone boiler with no control board. I appreciate you for the detailed information about the 5-wire thermostat terminal setup, including an unconnected 'C' black wire. I'll be glad to help you with the information you need!

Given the custom and non-standard wire color setup you've described, wiring incorrectly the Nest Power Connector can lead to safety hazards or damage to your system. For your safety and to ensure the correct operation of your boiler, I recommend contacting an HVAC technician to inspect your wiring and complete the Nest Power Connector installation. They have the expertise to safely identify each wire's function and ensure proper operation.

Please refer to our helpful article to receive the best possible experience: Professional installation and service

If you have any other questions please don't hesitate to post them on this forum.

Best regards,
Juan