http://waterheatertimer.org/Two-water-heaters.html http://waterheatertimer.org/Water-heater-recirculation-system.html TWO RESIDENTIAL/LD ATMOSPHERIC VENT MODELS WITH RETURN CIRCULATION & INTEGRATED MIXING DEVICE THIS DRAWING SHOWS A SUGGESTED PIPING CONFIGURATION AND OTHER DEVICES; CHECK WITH LOCAL CODES AND ORDINANCES FOR ADDITIONAL REQUIREMENTS. *EXPANSION TANK RECOMMENDED TO MINIMIZE ANY PRESSURE BUILD UP IF THE WATER SUPPLY PIPING HAS A BACK-FLOW PREVENTER, CHECK VALVE OR WATER METER WITH A CHECK VALVE.
WATER SUPPLY
EXPANSION TANK* SHUT OFF VALVE
UNION
WATER SUPPLY BACK-FLOW PREVENTER
UNION CONNECT RECIRCULATION TO "R" CONNECTION ON IMD DETAIL
SHUT OFF VALVE SYSTEM RETURN
MIXED WATER CIRCULATOR
HONEYWELL INTEGRATED MIXING DEVICE (IMD)
RECIRCULATED WATER
C
REDUCER COUPLING
UNION
SHUT OFF VALVE
HONEYWELL INTEGRATED MIXING DEVICE (IMD)
MIXED WATER
COLD IN
UNION
SHUT OFF VALVE
MIXED WATER
"AH" CONNECTOR
BACK-FLOW PREVENTER
SHUT OFF VALVE
UNION TEMPERATURE AND PRESSURE RELIEF VALVE
UNION
TEMPERATURE AND PRESSURE RELIEF VALVE
DISCHARGE TUBE
DISCHARGE TUBE
DRAIN
"R" CONNECTOR DRAIN OUTLET HOT CONNECTOR
DRAIN
DRAIN OUTLET