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Viessmann LLH w/ sensor - function.
First -- Does Viessmann supply the sensor with the header? Or is this an additional part. Also -- I get that it's measuring the temperature on top of the header. But why ? Is not the boiler measuring the return temp anyway ? Or am I incorrect and the boiler does not have a way of measuring the return water temp? If it does not .. I get why it would like the header temp.
Looks like the 200 uses a 7134 791 header (80/50)