A.O. Smith GWH-400N, GWH-500N, GWH-650N, GWH-750N, GWH-1000N User Manual

Commercial Gas Circulating

Water Heaters

BURKAY® GENESIS

85% EFFICIENT, ULTRA-LOW NOx HOT WATER HEATER

A. O. Smith Genesis® Water Heaters offer everything you could ask for in a non-condensing water heater. They provide a near condensing 85% thermal efficiency, outstanding venting flexibility, space-saving stackable design and a clean burning fan assisted combustion system with low NOx emissions that meet the most stringent California standards.

ELECTRONIC CONTROL WITH PRECISE TEMPERATURE MANAGEMENT

•Controls every electrical water heater function, including pump operation and main burner ignition, delivers precise temperature management, with ±1º accuracy.

•Display panel shows current operating status and fault readings

•Display also shows temperature setpoints, outlet temperature, current inlet/outlet differential (DT) and tank temperature.

•Included remote temperature sensor when mounted in the storage tank allows the tank temperature to be set and monitored at the water heater.

STAGE GAS FIRING SYSTEM

•Prevents short cycling and ensures smooth operation, saves fuel and extends product life.

•Delivers maximum output when demand is high, reduced firing rates during off peak times.

SPACE-SAVING DESIGN

•Optional stack rack allows one unit to be stacked on top of another, doubling output within the footprint of a single unit.

•If floor space is limited, the Genesis water heater can be installed outdoors with an optional outdoor Vent Cap.

MEETS ASHRAE/IESNA 90.1-2004 MULTIPLE VENTING OPTIONS

•All Genesis models can vent vertically in Category I with double wall “B” vent or horizontally in Category IV with AL29-4C stainless steel vent material.

FACTORY START-UP INCLUDED

•Required for activating warranty and assuring maximum operating performance. Contact your local sales representative or Authorized Start-Up Agent to arrange a FREE Certified Start-Up.

ULTRA-LOW NOx OPERATION

• Meets SCAQMD Rule 1146.2 air quality standards.

COPPER FINNED-TUBE HEAT

EXCHANGER

•Gasketless glasslined headers and copperfinned tubes with extruded integral fins deliver exceptional heat transfer.

•Copper is lightweight for easier handling and immune to thermal shock.

5-YEAR LIMITED HEAT EXCHANGER WARRANTY

•For complete warranty information, consult written warranty or contact A. O. Smith.

GWH-400 THRU GWH-2100

©2015 A. O. Smith Corporation. All rights reserved.	Page 1 of 4
www.hotwater.com | 800-527-1953 Toll-Free USA | A. O. Smith Corporation | 500 Tennessee Waltz Parkway | Ashland City, TN 37015	AOSCG25200

Commercial Gas Circulating

Water Heaters

OTHER GENESIS® FEATURES

•Stage Firing – 2 Stages

•Sealed Combustion Chamber

•Stainless Steel Burners

•Low NOx Operation

•All Bronze Circulating Pump (Shipped Loose)

•On/Off Switch

•Adjustable High Limit w/ Manual Reset

•Pump Delay

•ASME Copper Finned Tube Heat Exchanger Certified “HLW” Stamped 160 PSI Working Pressure

•ASME Temperature & Pressure Relief Valve 125#

•Factory mounted Flow Switch

•BMS Terminal Strip

•Contacts for Air Louvers

•Contacts on any Failure

GENESIS® OPTIONS

•Cupro-Nickel Heat Exchanger

•High Gas Pressure Switch w/ Manual Reset

•Low Gas Pressure Switch w/ Manual Reset

•Low Water Cut-Off w/ Manual Reset & Test

•Stack Rack

•Combustible Floor Shield (400 – 750)

•International Voltage (230V 50Hz)

SEQUENCING PANEL – Can manage 1 to 4 two stage water heaters

•Includes remote Tank sensor and sensor well

•Controls each stage of multiple stage fired water heater(s) to meet system demand

•Provides Cascade/Lead-Lag operation when multiple units are connected

Inlet Gas Pressure

	Model	Natural				LP
		Max. W.C.	Min. W.C.		Max. W.C.		Min. W.C.
	400-1200	14.0		4.5	14.0		8.0

Do not exceed the maximum Inlet Pressure. Minimum inlet pressure is for the purpose of input adjustment.

			Amp Draw Data
	Model				Approx.
					Total
	Number	Controls	Blower	Pump Fla*
					Amp’s @
					120 VAC
	GWH-400N	3.6	2.7	5.8	12.1
	GWH-500N	3.6	2.7	5.8	12.1
	GWH-650N	5.4	3.4	5.8	14.6
	GWH-750N	5.4	3.4	5.8	14.6
	GWH-1000N	7.3	3.2	7.4	17.9
	GWH-1250N	7.3	3.2	7.4	17.9
	GWH-1450N	7.3	6.7	7.4	21.4
	GWH-1800N	7.3	6.7	7.4	21.4
	GWH-2100N	7.3	6.7	7.4	21.4

	DIRECT VENT	SIDEWALL
	OUTDOOR	DUCTED AIR
		w/SIDEWALL INLET
	POWERED SIDEWALL	DIRECT VENT
	W/DUCTED INTAKE	VERTICAL

CONVENTIONAL

POWERED

SIDEWALL

MULTIPLE VENTING OPTIONS

The Genesis models offer eight venting options to meet the most challenging installation requirements. The Genesis can vent vertically in Category I with double wall “B” vent or horizontally in Category IV with AL29-4C stainless steel vent material.

Note: For the most current Genesis venting distances/information, consult the Genesis Product Manual, available through your local A. O. Smith representative, or online at www.hotwater.com.

Model	Vent	Combustion		Maximum Equivalent Feet of Pipe
					Powered		Ducted Air
	Outlet		Sidewall	Powered		Direct Vent
Number	Size	Air Inlet		Sidewall	Sidewall w/		w/Sidewall
					Ducted Air		Intake
GWH-400N	6”	6”	50’	50’	50’/50’	50’/50’	50’
GWH-500N	6”	6”	50’	50’	50’/50’	50’/50’	50’
GWH-650N	8”	8”	50’	50’	50’/50’	50’/50’	50’
GWH-750N	8”	8”	50’	50’	50’/50’	50’/50’	50’
GWH-1000N	10”	10”	50’	100’	100’/100’	50’/50’	50’
GWH-1250N	12”	12”	50’	100’	100’/100’	50’/50’	50’
GWH-1450N	12”	12”	50’	100’	100’/100’	50’/50’	50’
GWH-1800N	14”	12”	50’	100’	100’/100’	50’/50’	50’
GWH-2100N	14”	12”	50’	100’	100’/100’	50’/50’	50’

Note: 90 degree ells = 5’ of pipe, 45 degree ells = 2 1/2’ feet of pipe

©2015 A. O. Smith Corporation. All Rights Reserved	Page 2 of 4
www.hotwater.com | 800-527-1953 Toll-Free USA | A. O.Smith Corporation | 500 Tennessee Waltz Parkway | Ashland City, TN 37015	AOSCG25200