A.O. Smith 650A, 740A Water Heater User Manual


 
16
CAUTION: IF BUILDING COLD WATER SUPPLY HAS A
BACKFLOW PREVENTER, CHECK VALVE OR WATER
METER WITH CHECK VALVE, PROVISIONS FOR
THERMAL EXPANSION OF WATER IN THE HOT WATER
SYSTEM MUST BE PROVIDED.
TWO TEMPERATURE - THREE HEATERS (TWO PRE-HEATERS/ONE BOOSTER)
WITH OR WITHOUT BUILDING RECIRCULATION
TWO TEMPERATURE - TWO HEATERS (ONE PRE-HEATER/ONE BOOSTER HEATER)
WITH OR WITHOUT BUILDING RECIRCULATION
FOR MULTIPLE HEATER INSTALLATION SEE
MANIFOLD KIT SPECIFICATIONS, PAGE 18.
* PIPE RELIEF VALVE TO OPEN DRAIN.
** 140°F TO 150°F SHOULD BE MAXIMUM
WATER TEMPERATURE MAINTAINED IN THE
PRE-HEATERS.
120°F SHOULD BE THE MINIMUM
TEMPERATURE OF WATER IN THE PRE-
HEATERS.
CONNECT CIRCULATING LINE FROM FIXTURES, IF
USED, TO COLD WATER SUPPLY LINE OF PRE-
HEATER.
CONNECT CIRCULATING LINE OF 180°F OR BOOSTED
WATER, IF USED, TO INLET WATER LINE TO BOOSTER.
INSTALL IN ACCORDANCE WITH LOCAL CODES.
DANGER
TEMPERATURE SETTING SHOULD NOT EXCEED SAFE TEMPERATURE AT
FIXTURES. SEE WATER TEMPERATURE CONTROL WARNING ON PAGE 23. IF
HIGHER PREHEAT TEMPERATURES ARE NECESSARY TO OBTAIN ADEQUATE
BOOSTER OUTPUT, ADD AN ANTI-SCALD VALVE FOR HOT WATER SUPPLIED TO
FIXTURES.
CIRCULATING PUMP WIRING DIAGRAM