... ) used in hot water systemBLUEWATER control valves (6600, 6800, 7800, 8600, 8,800) are optional as hot water system (temperature ≤65 ... installed in tanks side, BLUEWATER control valves 6600, 6800, 7800, 8600 8800 all have this option,.7) additional microswitchControl valves through ...