A.O. Smith BTN 120-40D User Manual

Commercial Gas Water Heaters

MasterFit® Low Nox Commercial Gas Tank-Type
Water Heaters

APPROVAL RATINGS AND CERTIFICATION

All models comply with ANSI Z21.10.3 CSA4.3
All models comply with ASHRAE/IES 90.1-2004
C.E.C. California Energy Commission
All models comply with Texas and So. California
SCAQMD Rule 1146.2

FEATURES

Eighty plus percentage thermal effi ciency affords lower operating costs on
most models.

INDUCED DRAFT BUILT-IN BLOWER

mounted and wired. Ideal for installations where negative pressure is present in the building.
Blower proves draft prior to ignition. No drafthood or barometric damper required.

METAL VENTING - Rated Category I Appliance. Uses standard metal single wall or double

wall type “B” vent. Can be commonly vented with other Category I appliances. Vent connects
directly to the blower outlet. Perfect choice for retrofi t and upgrade installations.

WATER CONNECTIONS - For ease of installation, all BTNs feature water connections on the

top, front, and rear.

GLASS LINED TANK - Permaglas® Ultracoat is the proprietary ceramic coating developed

by A. O. Smith’s ceramic engineers specifi cally for the heater. It is applied after the complete
tank has been assembled to give a seamless barrier against hot water corrosion. The maximum
working pressure is 160 psi.

INSTALLED COST SAVINGS - When multiple BTN units are exclusively used in a vent

manifold, use the National Flue Gas Code Table 11 Fan Sizing Charts to determine vent
diameter and specifi cations. The BTN with its internal induced draft blower enables safe use of
smaller vent diameters. This feature can save hundreds of dollars in installation costs.

- The blower is built into the top cover, factory

MODELS

BTN

120-400(A)

FULLY AUTOMATIC DIGITAL CONTROLS WITH SAFETY SHUTOFF - Accurate,

dependable control system. Manual reset gas shutoff device for added safety. Maximum inlet
gas pressure is 14” W.C. Minimum gas pressure is 5.0” W.C. Natural Gas, 11” W.C. Propane.

FOAM INSULATION - Saves fuel, helps reduce standby heat loss.

JACKET- Heavy gauge steel fi nished with a baked enamel fi nish over a bonderized undercoat.

EASY CLEANING - Handhole cleanout allows access for easy cleaning.

FULLY TESTED FOR SAFETY AND PERFORMANCE - Design certifi ed by the

Underwriters Laboratory for 180°F hot water service. Meets rigid requirements of the National
Sanitation Foundation when equipped with optional leg kit. Certifi ed for use on combustible
fl ooring.

INTERMITTENT IGNITION DEVICE - Eliminates standing pilot. Provides fl ame failure

response in less than one second. Power ON/OFF switch.

EASY TO INSTALL - Completely factory-assembled. Only gas, water, vent and electric

connections need be made. Provided with drain valve.

ANODES - CoreGuard™ long-life, stainless steel core anode rods.

PLUG KITS - Pipe nipples and caps are included to plug unused water connections.

Revised September 2008

Approved to NSF Standard 5
with option leg kit.

on selected models.

AOSCG10500

PG 1 OF 4

Commercial Gas Water Heaters

OTHER FEATURES

• Equipped with gas pressure regulator and pilot fi lter • Integral automatic gas shutoff system prevents excessive water temperature •
A.G.A. rated temperature and pressure relief valve factory-installed • Maximum working pressure is 160 psi standard • Cathodic protection

• Adjustable thermostat with a 120-180°F range.

• THREE YEAR LIMITED TANK WARRANTY – For complete warranty information, consult written warranty or contact A. O. Smith.

OPTIONS

• Manifold kits for multiple heater installations.

• Meets NSF Standard 5 with optional leg kit.

BTN DIA-SCAN™ CONTROLS

The A.O. Smith BTN models feature true self diagnostic controls in a digital solid state design. These advanced control aid in both the
installation and maintenance of the BTN water heater. The White Rogers Silicon Nitride Hot Surface Ignitor ensures rugged reliability and
years of trouble free operation.

Digital Temperature Control

Solid State Ignition Control

Solid State Temperature Probe

Silicon Nitride Hot Surface Ignitor

Digital Temperature Control

• Accuracy to within ± 2°F

• Power On/Standby Indicator

• ECO Open Indicator

• Reset Status Indicator

• Heating-Mode Indicator

Solid State Ignition Control

• Power On/Standby Indicator

• Gas Valve Circuit Monitor

• Reverse Polarity Indicator

• Improper Grounding Error Indicator

• Lock Out Condition Indicator with Auto Retry

• Low Gas Pressure & Blower Prover Indicator

• Weak Flame Sense Indicator

• Combustion Operation Indicator

• Call for Heat Indicator

Solid State Temperature Probe

• Solid State Thermistor Technology

• Plus or minus 2°Fahrenheit

• Direct immersion package

Silicon Nitride Hot Surface Ignitor

• Rugged

• Dependable

• Separate Flame Prover Rod

• Quick connect terminals

• Adaptive learning technology extends ignitor life

www.hotwater.com

Revised September 2008

AOSCG10500

PG 2 OF 4