Just from the wording, ignoring the numbers, this looks like the control connection (red +5v,black ground and the last one signal).
From your description is guess this connects to the boiler on a dedicated port which provides the DC and reads the signal. 5v is quite common for sensors so that doesn’t seem off.
Just from the wording, ignoring the numbers, this looks like the control connection (red +5v,black ground and the last one signal).
From your description is guess this connects to the boiler on a dedicated port which provides the DC and reads the signal. 5v is quite common for sensors so that doesn’t seem off.