Just had a new (replacement) Weil-McLain Gold GV series 4 boiler installed. This unit heats fluid that is piped thru a basement floor.
The old unit, that rusted out (15 years old), had a lower outlet temperature. That unit supplied fluid at about 120F into the floor. This new unit is up around 140F.
I assume that the oulet temperature, at 140F, is related directly to the boiler inlet temperature; it's the same circuit. I'm guessing.. I don't have a schematic. My desire to reduce this temperature is based on increasing the boiler efficiency.
The user's manual says that the GCM (the units controller) mixes return water (cooled by the floor) and by-passed boiler output to maintain 140F temperature into the boiler sections, "to guard against condensation even if the return water is as low as 6oF". Fluid returned from the floor is around 60F.
My questions are these.
Can the boiler inlet temperature be adjusted?
Would it be more efficient to lower the boiler inlet temperature?
Would lowering the temperature to, say, 120 be a good idea?
What is the reason to avoid condensation? Doesn't the condensate just flow into a drain?