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Where to connect Outdoor sensor on WM CGa4 PIDN Series 3 boiler

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mariusz6100
mariusz6100 Member Posts: 9
edited November 2025 in Radiant Heating

Hello, I am having difficulty finding information on how to connect the Outdoor Temperature Sensor Kit, 381-356-586 to CGa4-PIDN series 3 boiler control unit. There is no drect plug in where I can connect the harness provided with the kit and there are no instructions how to connect it. I have not found any information whether an outdoor reset kit is also reuqired. From what I could find, it would seem I should be able to connect the sensor to the contiol unit directly.

The control unit has ODT terminal for 1 wire which seems to be outdoor temperature sensor at C9-1 (same as P9-1 on the other wiring diagram), but I have no idea where I should plug in the second wire and whether C9-2 24VAC Common is the right spot (same as P9-2 on the other wiring diagram). Or I may be misreading the diagram all together.

Any heklp is apreciated and I am including pics of the diagram and control board.

Here is the manual diagram, there is no connection to the harness on the control board:

image.png image.png


Here is the diagram from the boiler

IMG_1901.jpg IMG_1902.jpg



And here is the pic of the control unit

IMG_1906.jpg IMG_1915.jpg IMG_1914.jpg IMG_1916.jpg

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