tech_support January 11, 2019 Shad, the 521619A will control from 1 GPM to over 10 GPM. Having one for each loop will be overkill. Suggest having one to serve all 6 zones, or one for your 4-zone and one for your 2-zone for better control. Reply
Shad, the 521619A will control from 1 GPM to over 10 GPM. Having one for each loop will be overkill. Suggest having one to serve all 6 zones, or one for your 4-zone and one for your 2-zone for better control.