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Master-Fit® Ultra-Low NOx Commercial Gas Water Heaters
Unit of Measure
Items Master-Fit® Ultra-Low NOx Commercial Gas Water Heaters
BTL-120
Master-Fit® Ultra-Low NOx Commercial Gas Water Heaters
Master-Fit® Ultra-Low NOx Commercial Gas Water Heaters
BTL-154
Master-Fit® Ultra-Low NOx Commercial Gas Water Heaters
Master-Fit® Ultra-Low NOx Commercial Gas Water Heaters
BTL-275(A)
Master-Fit® Ultra-Low NOx Commercial Gas Water Heaters
Master-Fit® Ultra-Low NOx Commercial Gas Water Heaters
BTL-310(A)
Master-Fit® Ultra-Low NOx Commercial Gas Water Heaters
Master-Fit® Ultra-Low NOx Commercial Gas Water Heaters
BTL-366(A)
Master-Fit® Ultra-Low NOx Commercial Gas Water Heaters
Manufacturer N/A A. O. Smith®
Equipment Grade N/A Commercial
Schematic N/A
Schematic Drawing for Master-Fit® Ultra-Low NOx Commercial Gas Water Heaters (BTL-120 to BTL-250(A))
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Schematic Drawing for Master-Fit® Ultra-Low NOx Commercial Gas Water Heaters (BTL-120 to BTL-250(A))
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Schematic Drawing for Master-Fit® Ultra-Low NOx Commercial Gas Water Heaters (BTL-275(A) to BTL-400(A))
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Schematic Drawing for Master-Fit® Ultra-Low NOx Commercial Gas Water Heaters (BTL-275(A) to BTL-400(A))
N/A
Schematic Drawing for Master-Fit® Ultra-Low NOx Commercial Gas Water Heaters (BTL-275(A) to BTL-400(A))
Dimension A N/A 68-1/4 in173.4 cm N/A 68-1/4 in173.4 cm N/A 76 in193 cm N/A 76 in193 cm N/A 76 in193 cm
Dimension B N/A 9-1/2 in22.86 cm N/A 9-1/2 in22.86 cm N/A 16-1/4 in41.2 cm N/A 16-1/4 in41.2 cm N/A 16-1/4 in41.2 cm
Dimension C N/A 70-1/2 in179.1 cm N/A 70-1/2 in179.1 cm N/A 78-1/4 in198.8 cm N/A 78-1/4 in198.8 cm N/A 78-1/4 in198.8 cm
Dimension D N/A 58-1/4 in147.8 cm N/A 58-1/4 in147.8 cm N/A 65-3/4 in167 cm N/A 65-3/4 in167 cm N/A 65-3/4 in167 cm
Dimension E N/A 26-1/4 in66.5 cm N/A 26-1/4 in66.5 cm N/A 25-3/4 in65.4 cm N/A 25-3/4 in65.4 cm N/A 25-3/4 in65.4 cm
Dimension F N/A 21 in53.3 cm
Dimension G N/A 1/2 NPT N/A 1/2 NPT N/A 3/4 NPT N/A 3/4 NPT N/A 3/4 NPT
Dimension H N/A 58-1/2 in148.8 cm N/A 58-1/2 in148.8 cm N/A 66-1/4 in168.3 cm N/A 66-1/4 in168.3 cm N/A 66-1/4 in168.3 cm
Dimension I N/A 6 in15.2 cm
Dimension J N/A 27-3/4 in70.5 cm
Dimension K N/A 1-1/2 NPT
Dimension L N/A 1-1/2 NPT
Dimension M N/A 38-1/2 in97.8 cm N/A 38-1/2 in97.8 cm N/A 41 in104 cm N/A 41 in104 cm N/A 41 in104 cm
Input Power N/A 120000 KBTU/hr35 kW N/A 154000 KBTU/hr45 kW N/A 275000 KBTU/hr81 kW N/A 310000 KBTU/hr91 kW N/A 366000 KBTU/hr107 kW
Capacity N/A 81 U.S. gal307 L N/A 81 U.S. gal307 L N/A 85 U.S. gal322 L N/A 85 U.S. gal322 L N/A 85 U.S. gal322 L
Thermal Efficiency N/A 82 %
Recovery at 36 ºF Temperature Rise N/A 331 gal/h N/A 425 gal/h N/A 754 gal/h N/A 849 gal/h N/A 1003 gal/h
Recovery at 20 ºC Temperature Rise N/A 1254 L/h N/A 1609 L/h N/A 2853 L/h N/A 3216 L/h N/A 3797 L/h
Recovery at 40 ºF Temperature Rise N/A 298 gal/h627 L/h N/A 383 gal/h805 L/h N/A 678 gal/h1426 L/h N/A 765 gal/h1608 L/h N/A 903 gal/h1898 L/h
Recovery at 22 ºC Temperature Rise N/A 1129 L/h N/A 1448 L/h N/A 2567 L/h N/A 2894 L/h N/A 3417 L/h
Recovery at 50 ºF Temperature Rise N/A 239 gal/h N/A 306 gal/h N/A 543 gal/h N/A 612 gal/h N/A 722 gal/h
Recovery at 28 ºC Temperature Rise N/A 903 L/h N/A 1159 L/h N/A 2054 L/h N/A 2315 L/h N/A 2734 L/h
Recovery at 54 ºF Temperature Rise N/A 221 gal/h N/A 283 gal/h N/A 502 gal/h N/A 566 gal/h N/A 669 gal/h
Recovery at 30 ºC Temperature Rise N/A 836 L/h N/A 1073 L/h N/A 1902 L/h N/A 2144 L/h N/A 2531 L/h
Recovery at 60 ºF Temperature Rise N/A 199 gal/h N/A 255 gal/h N/A 452 gal/h N/A 510 gal/h N/A 602 gal/h
Recovery at 33 ºC Temperature Rise N/A 752 L/h N/A 966 L/h N/A 1712 L/h N/A 1929 L/h N/A 2278 L/h
Recovery at 70 ºF Temperature Rise N/A 170 gal/h N/A 219 gal/h N/A 388 gal/h N/A 437 gal/h N/A 516 gal/h
Recovery at 39 ºC Temperature Rise N/A 645 L/h N/A 828 L/h N/A 1467 L/h N/A 1654 L/h N/A 1953 L/h
Recovery at 72 ºF Temperature Rise N/A 166 gal/h N/A 213 gal/h N/A 377 gal/h N/A 425 gal/h N/A 501 gal/h
Recovery at 90 ºF Temperature Rise N/A 149 gal/h N/A 191 gal/h N/A 339 gal/h N/A 382 gal/h N/A 451 gal/h
Recovery at 50 ºC Temperature Rise N/A 502 L/h N/A 644 L/h N/A 1141 L/h N/A 1286 L/h N/A 1519 L/h
Recovery at 100 ºF Temperature Rise N/A 119 gal/h N/A 153 gal/h N/A 271 gal/h N/A 306 gal/h N/A 361 gal/h
Recovery at 56 ºC Temperature Rise N/A 451 L/h N/A 579 L/h N/A 1027 L/h N/A 1158 L/h N/A 1367 L/h
Recovery at 108 ºF Temperature Rise N/A 110 gal/h N/A 142 gal/h N/A 251 gal/h N/A 283 gal/h N/A 334 gal/h
Recovery at 60 ºC Temperature Rise N/A 418 L/h N/A 536 L/h N/A 951 L/h N/A 1072 L/h N/A 1266 L/h
Recovery at 110 ºF Temperature Rise N/A 108 gal/h N/A 139 gal/h N/A 247 gal/h N/A 278 gal/h N/A 328 gal/h
Recovery at 61 ºC Temperature Rise N/A 410 L/h N/A 527 L/h N/A 934 L/h N/A 1052 L/h N/A 1243 L/h
Recovery at 120 ºF Temperature Rise N/A 99 gal/h N/A 128 gal/h N/A 226 gal/h N/A 255 gal/h N/A 301 gal/h
Recovery at 67 ºC Temperature Rise N/A 376 L/h N/A 483 L/h N/A 856 L/h N/A 965 L/h N/A 1139 L/h
Recovery at 126 ºF Temperature Rise N/A 95 gal/h N/A 121 gal/h N/A 215 gal/h N/A 243 gal/h N/A 287 gal/h
Recovery at 70 ºC Temperature Rise N/A 358 L/h N/A 460 L/h N/A 815 L/h N/A 919 L/h N/A 1085 L/h
Recovery at 130 ºF Temperature Rise N/A 92 gal/h N/A 118 gal/h N/A 209 gal/h N/A 235 gal/h N/A 278 gal/h
Recovery at 72 ºC Temperature Rise N/A 347 L/h N/A 446 L/h N/A 790 L/h N/A 890 L/h N/A 1051 L/h
Recovery at 140 ºF Temperature Rise N/A 85 gal/h N/A 109 gal/h N/A 194 gal/h N/A 218 gal/h N/A 258 gal/h
Recovery at 78 ºC Temperature Rise N/A 322 L/h N/A 414 L/h N/A 734 L/h N/A 827 L/h N/A 976 L/h
Type N/A Natural Gas
Minimum Gas Supply Pressure N/A 0.87 kPa15 inWc
Maximum Gas Supply Pressure N/A 14 inWc3.48 kPa
Voltage N/A 120 V
Frequency N/A 60 Hz
Current N/A <5 A
Sides and Rear Clearance to Combustibles N/A 0 in
Top Cover Clearance to Combustibles N/A 12 in
Sides and Rear Clearance to Non-Combustibles N/A 0 in
Top Cover Clearance to Non-Combustibles N/A 12 in
Top Inlet Water Connection N/A 1-1/2 in
Front Inlet Water Connection N/A 1-1/2 in
Back Inlet Water Connection N/A 1-1/2 in
Top Outlet Water Connection N/A 1-1/2 in
Front Outlet Water Connection N/A 1-1/2 in
Back Outlet Water Connection N/A 1-1/2 in
Standard Approximate Shipping Weight N/A 750 lb340 kg N/A 750 lb340 kg N/A 850 lb386 kg N/A 850 lb386 kg N/A 850 lb386 kg
ASME Approximate Shipping Weight N/A N/A N/A 900 lb408 kg N/A 900 lb408 kg N/A 900 lb408 kg
Industry Standards N/A ANSI Z-21.10.3 - CSA 4.3 ASHRAE/IESNA 90.1 ASME Certified
Features N/A 82% thermal efficiency means lower operating costs.

Fan Assisted Combustion - The blower is built into the Low NOx burner assembly for Ultra-Low NOx readings that comply with SCQAMD rule1146.2 of 14 ng/j or 20 ppm.

Metal Venting - Rated Category I Appliance. Uses standard double wall type "B" vent. Can be commonly vented with other Category I appliances. Vent connects directly to the vent connector outlet. No Draft hood or barometric damper required. Perfect choice for retrofit and upgrade installations.

Water Connections - For ease of installation, all BTLs feature water connections on the top, front, and rear. "The Eliminator™" inlet water connection eliminates harmful scale buildup, extending the life of the product. The front inlet connection must be used for the Eliminator™ benefits.

Glass Lined Tank - Permaglas® Ultracoat is the proprietary ceramic coating developed by A. O. Smith®’s ceramic engineers specifically for the heater. It is applied after the complete tank has been assembled to give a seamless barrier against hot water corrosion.

Installed Cost Savings - When multiple BTL units are exclusively used in a vent manifold, use the National Fuel Gas Code Table 13 Vent Sizing information to determine vent diameter and specifications. The BTL often uses a smaller vent diameter than a natural draft water heater which saves on installation cost.

Fully Automatic Digital Controls with Safety Shutoff - Accurate, dependable control system. Features a two speed blower control for smooth main burner light-off. Manual reset gas shutoff device for added safety. Maximum inlet gas pressure is 14" W.C. Minimum gas pressure is 3.5" W.C. Natural Gas.

Foam Insulation - Saves fuel, helps reduce standby heat loss.

Jacket - Heavy gauge steel finished with a baked enamel finish over a bonderized undercoat.

Easy Cleaning - Handhole cleanout allows access for easy cleaning.

Intermittent Ignition Device - Eliminates standing pilot. Provides flame failure response in less than one second. Spark igniter and 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.
Other Standard Features N/A
  • Integral automatic gas shutoff system prevents excessive water temperature
  • CSA Certified and ASME Rated T&P Relief valve are factory-installed
  • Maximum working pressure is 160 psi standard
  • Adjustable thermostat with a 120 to 180 ºF range.
  • All models certified up to 7700 ft.
Testing and Certifications N/A Fully Tested for Safety and Performance - Design certified by the Underwriters Laboratory for 180°F hot water service. Meets rigid requirements of the National Sanitation Foundation when equipped with optional leg kit. Certified for use on combustible flooring.

Approval Ratings and Certification - All models meet ANSI Z21.10.3 - CSA® 4.3 standards and the thermal efficiency and standby loss requirements of the U.S. Department of Energy and current edition of ASHRAE/IESNA 90.1.

NSF LEG Kit
  • Meets NSF Standard 5 with optional leg kit - Part #9008214005
Models available for sale in California only.
Warranty N/A
  • 3-Year Tank Warranty / 1-Year Parts Limited Warranty.
Note N/A A after model number designates ASME construction.

Dimensions and specifications subject to change without notice in accordance with our policy of continuous product improvement.