A.O. Smith 404 - Manual (Page 19)

19
ONE GENESIS (MODEL GW) HOT WATER SUPPLY BOILER WITH HORIZONTAL TANK
Figure 12. Tank probe installation.
PRESSURE RELIEF VALVE RATING SHOULD
NOT EXCEED PRESSURE CAPACITY OF ANY
COMPONENT IN THE SYSTEM.
PIPING SHOULD CONFORM TO LOCAL CODES.
BALL VALVES ARE SHOWN FOR SERVICING
BOILER. HOWEVER, LOCAL CODES SHALL
GOVERN THEIR USAGE.
DANGER
TEMPERATURE SETTING SHOULD NOT EXCEED
SAFE USE TEMPERATURE AT FIXTURES.
SEE WATER TEMPERATURE CONTROL
WARNING ON PAGE 26. IF HIGHER PREHEAT
TEMPERATURES ARE NECESSARY TO OBTAIN
ADEQUATE BOOSTER OUTPUT, ADD AN
ANTI-SCALD VALVE FOR HOT WATER
SUPPLIED TO FIXTURES.
WARNING
THE WATER MANIFOLD IS NOT DESIGNED TO
SUPPORT THE WEIGHT OF THE WATER PIPING
SYSTEM. SPECIAL CARE MUST BE TAKEN TO
ENSURE PROPER SUPPORT.
Figure 11. Single boiler with horizontal tank.
IMPORTANT
WATER FLOW SWITCH PROTECTS THE
BOILER IN CASE OF WATER SERVICE
INTERRUPTION OR CIRCULATOR FAILURE.
• PIPE TO OPEN DRAIN
X FACTORY-INSTALLED ON UNIT
== SUPPLIED WITH UNIT
=
FIELD-INSTALLED
INSTALL THERMAL EXPANSION
TANK ON COLD WATER
SUPPLY LINE, IF CHECK VALVE
OR PRESSURE REDUCING
VALVE IS USED IN SUPPLY.
Encase field-supplied wires
between tank probe and junction
box with 1/2" field supplied
conduit. "Pigtails" of field-
supplied wires should be spliced
to "pigtails" of tank probe and
connected to 24 VAC junction box.
See figure 15. This conduit and
wiring should be separate from
any other conduit/wiring to guard
against EMI (electromagnetic
interference).
MINIMUM
PIPE SIZE
MODELS INCHES
GW-1000
THRU 2 1/2"
2500 NPT
FACTORY PUMP SIZING
BASED ON 50 EQUIVALENT
FEET (15.2 m) OF PIPE.
MODELS
CIRCULATING RETURN
LINE CONNECTIONS
• TEMPERED WATER LOOP, IF USED,
CONNECT TO POINT R.
• STORED TEMPERATURE WATER LOOP,
IF USED, CONNECT TO ANY OPENING
NEAR BOTTOM OF TANK.
TWO TEMPERATURE WATER
MIXING VALVE APPLICATION