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Tekmar 360 settings "Mix Target" versus :"Boiler Min"
HI folks, I moved into a house with a low mass radiant system with a Viessman VT100 boiler, a tekmar 360 and a tekmar mixing valve (Forget the model, not too important now).
I'm learning the system and have studied the manual to figure out the numerous settings. I know the theory behind keeping the boiler temp above 140degF to prevent flue gas condensation. But I think there seems to be a contradiction in the settings which may be a lack of understanding on my part or perhaps a manual that isn't clear on the thing.
I understand the boiler min to be the minimum temperature for the 360 to open the mixing valve. So if say the boiler min was set to 180degF, the 360 will not command the mixing valve to open until the boiler supply is registering (close to) 180degF. I tested this by setting the boiler min to like 120 and watched once mixing demand was triggered the boiler temp rise and the mixing valve opened.
However, it seems to me that this contradicts the definition of mix target. For argument sake here, say the 360 is set to setpoint control, which is a fixed mixing target. without the need of an outside sensor. What happens if the mix target is fixed at 140deg? From the manual, this sounds like the mixing valve will never be opened and the heat will never work. because if the 360 is trying to send 140deg through the distribution, the boiler min will prevent the mixing valve from opening and this to me sounds like a contradiction or a stalemate. What am I missing? Will the 360 simply keep firing the boiler until the boil temp reaches 180deg overriding the mix target or will this be an endless tugowar? To me, as a software engineer by trade, this is a software design issue and essentially the boiler min overrides the mix target. I would think some kind of warning or say indication would be a nice thing.
Can somebody explain the precise steps of the operation given this scenario?