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A header without a hydraulic separator
As with my last post, a lack of room may have caused some mistakes to be made. A Rinnai condensing 155000 btu tankless heater was used to heat 3 different loads. A 3 season type room, all glass walls, cathedral but well insulated roof. 16x28 room with a 7x14 5 foot deep concrete pool/spa sitting in the floor. This did not leave much room around the pool for pex in the slab. 400 ft. 5/8 in the floor on one pump, a 10000btu European style radiator on one the few spots on the wall used as a towel warmer/ radiator, and a large HX to heat the pool fast. The header does not provide hot enough water when everything is calling for heat. And adding up all loads together comes nowhere near 150000 btus. The pumps are fighting each other with none having priority over the other.
Has anyone had good luck with Caleffis 559 series combination separator/ manifolds? They have in and out for the boiler and can be ordered with many configurations of zones all in one unit. This way I can use a larger pump to push water through the rather low volume of flow heater. And have separate zones for each load all able to fit in the tight space that was left for this equipment.