Hello All Overall I think my system is working well (Its saving me money), But I think the loop flow rates may be high causing low loop delta T. The Installer is trying to find his notes from the install and hasn’t got back to me with the measured flow rates. My crude calculation come up with 14 GPM and may explain the low delta T measurements. Is there a value that is too high? Everything I see listed from WF says 2-3 GPM per ton and the performance data tables only goes up to 8 GPM for my system. Should flow be set (restricted) for a certain delta T? I have a Water Furnace Envision NVD026B111CTL 2 Ton, 2 Stage, ECM blower with Desuperheater. I have attached a PDF file that I created this weekend to document my system performance for my future reference and it has all of my system particulars that I have access to. Tonight I will turn off my desuperheater and take EWT and LWT measurements and try and calculate flow rates. I have also thought about playing with the valves to reduce flow to get a delta T in the range of 5-8°F and see what effect it has on system performance. Any advice or insight would be appreciated, Thanks Richard.