http://waterheatertimer.org/Two-water-heaters.html http://waterheatertimer.org/Water-heater-recirculation-system.html THREE RESIDENTIAL/LD ATMOSPHERIC VENT MODELS WITH RETURN CIRCULATION SHUT OFF VALVE
THIS DRAWING SHOWS A SUGGESTED PIPING CONFIGURATION AND OTHER DEVICES; CHECK WITH LOCAL CODES AND ORDINANCES FOR ADDITIONAL REQUIREMENTS.
SYSTEM RETURN
CIRCULATOR
WATER SUPPLY
BACK-FLOW PREVENTER
*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.
BACK-FLOW PREVENTER
SHUT OFF VALVE
SHUT OFF VALVE UNION EXPANSION TANK*
SHUT OFF VALVE
SHUT OFF VALVE UNION
SHUT OFF VALVE UNION
SHUT OFF VALVE UNION
T&P RELIEF VALVE HOT WATER
DISCHARGE TUBE
UNION
T&P RELIEF VALVE DRAIN DRAIN OUTLET DISCHARGE TUBE
DRAIN OUTLET
SHUT OFF VALVE DRAIN DRAIN OUTLET SHUT OFF VALVE UNION DISCHARGE TUBE DRAIN
UNION T&P RELIEF VALVE
