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Not understanding relationship between WM ECO and Tekmar 262
I keep re-reading documentation and keep coming up with little gems that matter; but I did not see/understand that last couple of times I read the manual.
I have spent a lot of time trying to figure out how to get an additional outside thermistor to the ECO input for outside conditions. I just found a WM ECO manual sentence that says the otherwise required external thermistor can be dismissed, if a controller (e.g., 262) controls the boiler. I believe that the 262 gathers outside temperatures being fed to itself and the three additional 369 controllers.
Then the output of the 262 turns on/off the boiler control input for the ECO. I have seen nothing that implies this is an analog or digital data stream. Just a switch.
What I am just not understanding is how what appears to be an on/off signal from the 262 will properly manage the operation of a variable speed condensing boiler. Things like water temperature and modulating. The 269 seems to input a DHW demand and heat/not heat. I am just not getting it.
I have searched extensively, but pretty much always get pointed to the documentation I do not understand.
Can anyone help me understand this chain of control to me. Or point me to some explanations not published by Tekmar or WM. I am clearly not understanding something. But simple on/off does not seem right.