A. O. Smith BTH-120A User Manual

Commercial Gas Water Heaters

MODULATING BURNER ADVANCES THE
CYCLONE TO HIGHER LEVELS OF EFFICIENCY

FEATURES

The full line of A. O. Smith Cyclone Mxi condensing water heaters has been designed to
provide years of dependable service and feature industry leading technology. Models are
available from 120,000 to 500,000 Btu/h and all deliver thermal efficiencies of 95% and
higher. The unique helical coil heat exchanger limits weld joints for optimal service life
while maximizing heat transfer.

Cyclone is the industry leader in high efficiency commercial water heating with over a quarter
million Cyclones sold since 1996. The current Mxi modulating models adjust firing rate to the
specific demand further increasing efficiency and money savings.

BTH-120(A)

through

BTH-500(A)

INTELLIGENT CONTROL SYSTEM WITH LCD DISPLAY

nExclusive A. O. Smith designed control system
nProvides detailed water heater status information
nPrecise temperature control adjustable from 90 to 180 degrees
nBuilt-in diagnostics
nRun history information
nCyclone water heaters are compatible with the iCOMM™ remote

monitoring system. Call 1.888.928.3702 for more information.

SUBMERGED COMBUSTION CHAMBER, WITH HELICAL HEAT EXCHANGER COIL

nPositioned in center of tank, surrounded by water to virtually eliminate radiant heat

loss from chamber

nDirect spark ignition
nSpiral heat exchanger keeps hot burner gases swirling, uses centrifugal force to maximize

efficiency of heat transfer to water in tank

nSpiral heat exchanger reduces lime scale from forming on water-side surfaces, which

maintains energy efficiency over time

POWERED ANODES STANDARD ON ALL MODELS

nProvides long-lasting tank protection in varying water conditions
nPowered anodes are non-sacrificial
nAutomatically adjusts output needed to properly protect the tank

PERMAGLAS® ULTRA COAT™ GLASS LINING

nGlass coating is applied using a liquid slush coating technique to ensure uniform coating
nHeat exchanger coil is glassed both externally and internally for optimum protection

MECHANICAL VENTING VERSATILITY

nConventional power venting or direct venting
nVents vertically or through a sidewall
nFront located exhaust and condensate connections allow for easy install and access
nVents with low cost PVC Schedule 40 intake and exhaust pipe. Approved for optional

CPVC Schedule 40, Polypropylene and AL29-4C stainless steel vent materials

nDirect-vent intake and exhaust pipe can terminate separately outside building or through

single opening, using concentric vent assembly

nCanadian installations require ULC S636 PVC/CPVC, ULC S636 Polypropylene and AL29-4C

stainless steel pipe for intake and exhaust

1.888.WATER02

Model Shown:

100 Gallon

ANSl/NSF-5

HIGH EFFICIENCY MODULATING PRE-MIX POWERED BURNER

n Down-fired pre-mix burner provides optimum efficiency and quiet operation
n Top-mounted burner position prevents condensation from affecting burner operation

Revised June 2014

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Commercial Gas Water Heaters

OTHER CYCLONE Mxi FEATURES

SPACE-SAVING DESIGN FOR INSTALLATION FLEXIBILITY

nReduced footprint, ease of service, protection from water damage in case of flooding
nEasy-to-remove top cover for convenient access to serviceable parts
n0˝ installation clearances on sides and rear, 1-1/2˝ installation clearance on top
nHandhole cleanout allows easy access to tank interior for cleaning
n0˝ clearance to combustibles, approved for installation on combustible floors

CODES AND STANDARDS

nCSA certified and ASME rated T&P relief valve
nMaximum hydrostatic working pressure: 160 PSI
nAll models are design certified by Underwriters Laboratories (UL), Inc., to ANSI Z21.10.3 - CSA 4.3 Standards
nMeets the thermal efficiency and standby loss requirements of the U.S. Department of Energy and current edition ASHRAE/IESNA 90.1
nDesign-certified by Underwriters Laboratories to NSF standard 5 for 180°F (62°C) water
nComplies with SCAQMD Rule 1146.2 and other Air Quality Management Districts with similar requirements for low-NOx emissions
nASME tank construction optional on 120-500 model sizes

THREE-YEAR LIMITED TANK WARRANTY

nFor complete warranty details, consult written warranty shipped with heater, or contact A. O. Smith
(5-year tank extended warranty is optional)

OPTIONIAL KITS

nOptional Concentric Vent Kits
BTH-120 - 250 vent kit p/n 9006328005
BTH-300 - 500 vent kit p/n 9006144005

nOptional Low Profile Termination Vent Kits
3˝ Flush Mount Vent Kit p/n 9008933005
4˝ Flush Mount Vent Kit p/n 9008934005
6˝ Flush Mount Kit p/n 9008935005

nOptional Condensate Neutralization Kits
BTH-120-199 kit p/n 9007959005
BTH-250-500 kit p/n 9007960005

VENTING REQUIREMENTS

BTH-120(A) - 250(A)

NUMBER OF 90°

ELBOWS INSTALLED

One (1) 45 feet (13.7 meters) 115 feet (35.0 meters)
Two (2) 40 feet (12.2 meters) 110 feet (33.5 meters)

Three (3) 35 feet (10.7 meters) 105 feet (32.0 meters)

Four (4) 30 feet (9.1 meters) 100 feet (30.5 meters)
Five (5) N/A 95 feet (29.0 meters)

Six (6) N/A 90 feet (27.4 meters)

3 INCH PIPE 4 INCH PIPE

MAXIMUM FEET (METERS) MAXIMUM FEET (METERS)

BTH-300(A) - 500(A)

NUMBER OF 90°

ELBOWS INSTALLED

One (1) 65 feet (19.8 meters) 115 feet (35.0 meters)
Two (2) 60 feet (18.2 meters) 110 feet (33.5 meters)

Three (3) 55 feet (16.8 meters) 105 feet (32.0 meters)

Four (4) 50 feet (15.2 meters) 100 feet (30.5 meters)
Five (5) 45 feet (13.7 meters) 95 feet (29.0 meters)

Six (6) 40 feet (12.2 meters) 90 feet (27.4 meters)

4 INCH PIPE 6 INCH PIPE

MAXIMUM FEET (METERS) MAXIMUM FEET (METERS)

GAS PRESSURE REQUIREMENTS

MODEL

BTH-120(A) 0˝ W.C. (0 kPa) 0˝ W.C. (0 kPa) 4.4˝ W.C. (1.10 kPa) 8.5˝ W.C. (2.12 kPa) 14˝ W.C. (3.49 kPa) 14˝ W.C. (3.49 kPa)
BTH-150(A) 0˝ W.C. (0 kPa) 0˝ W.C. (0 kPa) 4.4 ˝ W.C. (1.10 kPa) 8.5˝ W.C. (2.12 kPa) 14˝ W.C. (3.49 kPa) 14˝ W.C. (3.49 kPa)
BTH-199(A) 0˝ W.C. (0 kPa) 0˝ W.C. (0 kPa) 4.4 ˝ W.C. (1.10 kPa) 8.5˝ W.C. (2.12 kPa) 14˝ W.C. (3.49 kPa) 14˝ W.C. (3.49 kPa)
BTH-250(A) 0˝ W.C. (0 kPa) 0˝ W.C. (0 kPa) 4.4 ˝ W.C. (1.10 kPa) 8.5˝ W.C. (2.12 kPa) 14˝ W.C. (3.49 kPa) 14˝ W.C. (3.49 kPa)
BTH-300(A) 0˝ W.C. (0 kPa) 0˝ W.C. (0 kPa) 4.8 ˝ W.C. (1.19 kPa) 8.5˝ W.C. (2.12 kPa) 14˝ W.C. (3.49 kPa) 14˝ W.C. (3.49 kPa)
BTH-400(A) 0˝ W.C. (0 kPa) 0˝ W.C. (0 kPa) 4.8 ˝ W.C. (1.19 kPa) 8.5˝ W.C. (2.12 kPa) 14˝ W.C. (3.49 kPa) 14˝ W.C. (3.49 kPa)
BTH-500(A) 0˝ W.C. (0 kPa) 0˝ W.C. (0 kPa) 4.8 ˝ W.C. (1.19 kPa) 8.5˝ W.C. (2.12 kPa) 14˝ W.C. (3.49 kPa) 14˝ W.C. (3.49 kPa)

MANIFOLD PRESSURE MINIMUM SUPPLY PRESSURE MAXIMUM SUPPLY PRESSURE

NATURAL GAS PROPANE GAS NATURAL GAS PROPANE GAS NATURAL GAS PROPANE GAS

For Technical Information and Automated Fax Service, call 800-527-1953. A. O. Smith Corporation reserves the right to make product changes or improvements without prior notice.

www.hotwater.com

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