A.O. Smith 402, 400, 401, 403, 405, 404 instruction manual Single boiler with horizontal tank

ONE GENESIS (MODEL GW) HOT WATER SUPPLY BOILER WITH HORIZONTAL TANK

INSTALL THERMAL EXPANSION TANK ON COLD WATER SUPPLY LINE, IF CHECK VALVE OR PRESSURE REDUCING VALVE IS USED IN SUPPLY.

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.

IMPORTANT

WATER FLOW SWITCH PROTECTS THE BOILER IN CASE OF WATER SERVICE INTERRUPTION OR CIRCULATOR FAILURE.

•PIPE TO OPEN DRAIN

XFACTORY-INSTALLED ON UNIT == SUPPLIED WITH UNIT

= FIELD-INSTALLED

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.

TWO TEMPERATURE WATER MIXING VALVE APPLICATION

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.

	MINIMUM
MODELS	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.

Figure 11. Single boiler with horizontal tank.

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).

Figure 12. Tank probe installation.

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