
®
Commercial Gas Water Heaters
SUGGESTED SPECIFICATION
Water Heater(s) shall be Model __________ as manufactured by A. O. SMITH, or equal. Water heater(s) shall be of glass-lined design,
and gasfired, equipped to burn natural gas and design certified by the Underwriter Laboratory under Volume III tests for commercial
heaters for delivery of 180°F water, and meet the thermal efficiency and standby loss requirements of the U.S. Department of Energy
and Current Edition of ASHRAE/IESNA 90.1. Heaters shall have an input rating of __________ and a recovery rating of
__________ GPH at a temperature rise of 100°F with a storage capacity of __________ gallons. Heaters shall be equipped with 1 1/2”
water inlet and outlet openings (BTN 200, 250, 275, 310 rear openings are 2”), a 2 3/4” x 3 3/4” boiler-type handhole cleanout and
shall have a maximum working pressure of 160 psi. Water heater(s) shall be equipped with an integrated control system consisting of
a 180°F adjustable thermostat with upper and lower sensing bulbs, which average the water temperatures at the top and bottom of
the tank for maximum water temperature control. Heater(s) shall be provided with a manual reset gas shutoff device, a gas pressure
regulator set for the type of gas supplied, coated steel burners, an approved draft diverter, anodes for cathodic protection, flue
damper and IID system. CSA Certified and ASME Rated T&P Relief Valve shall be furnished and installed by the factory. The heater
shall be insulated with foam insulation or equal. The outer jacket shall have a baked enamel finish over a bonderized undercoating.
All internal surfaces of the heater(s) exposed to water shall be glasslined with an alkaline borosilicate composition that has been
fused-to-steel by firing at a temperature range of 1400° to 1600°F. Heater tank shall have a 3 year limited warranty against corrosion
or sediment buildup as outlined in the written warranty. Fully illustrated instruction manual to be included.
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.
Revised April 2012
PG 4 OF 4
www.hotwater.com
AOSCG10500
Dimension Tables for BTN Models 120-400
Model
Approx.
Tank Cap.
(Gals.)
Type of
Gas
Input
Rating
Btu/Hr.
ABCDEFGHIJ
Approx. Ship.
Weight
Std. ASME
BTN120+71 nat 120,000 63 4 1/4 59 1/2 50 7/8 19 5/8 19 3/4 51 7/8 6 27 3/4 520 --
BTN154 81 nat 154,000 68 4 1/2 62 53 5/8 20 1/2 21 3/4 54 5/8 6 27 3/4 550 --
BTN180 100 nat 180,000 72 4 1/2 70 61 5/8 20 1/2 21 3/4 61 6 27 3/4 550 --
BTN199 100 nat 199,000 72 4 1/2 70 61 5/8 20 1/2 21 3/4 61 6 27 3/4 550 --
BTN199C* 93 nat 199,000 72 4 1/2 70 61 5/8 20 1/2 21 3/4 61 6 27 3/4 620 --
BTN200(A) 100 nat 199,000 72 4 1/2 70 61 5/8 20 1/2 21 3/4 61 6 27 3/4 660 710
BTN250(A) 100 nat 250,000 72 4 1/2 70 61 5/8 20 1/2 21 3/4 61 6 27 3/4 660 710
BTN275(A) 100 nat 275,000 72 4 1/2 70 61 5/8 20 1/2 21 3/4 61 6 27 3/4 660 710
BTN310(A)* 85 nat 310,000 73 4 1/2 72 62 1/2 20 1/2 21 3/4 63 6 27 3/4 720 770
BTN366(A) 85 nat 366,000 73 4 1/2 72 62 1/2 22 1/2 21 1 63 6 27 3/4 830 880
BTN400(A) 85 nat 390,000 73 4 1/2 72 62 1/2 22 1/2 21 1 63 6 27 3/4 830 880
Recovery Capacities for BTN
Model
Input
Rating
Btu/Hr.
Gal. 400F50
0F60
0F70
0F80
0F90
0F 1000F 1100F 1200F 1300F 1400F
BTN120 120,000 71 288 239 193 164 144 128 115 105 96 89 82
BTN154 154,000 81 369 295 247 211 185 184 148 134 123 114 106
BTN180 180,000 100 432 345 289 247 218 192 173 157 144 133 123
BTN199 199,000 100 477 382 319 273 239 212 191 174 159 147 136
BTN199C 199,000 93 477 382 319 273 239 212 191 174 159 147 136
BTN200(A) 199,000 100 477 382 319 273 239 212 191 174 159 147 136
BTN250(A) 250,000 100 600 480 401 343 300 266 240 218 200 184 171
BTN275(A) 275,000 100 659 528 441 377 332 293 264 240 220 203 188
BTN310(A) 310,000 85 743 595 497 425 372 330 297 270 248 229 212
BTN366(A) 366,000 85 878 702 587 502 439 390 351 319 293 270 251
BTN400(A) 390,000 85 935 748 626 534 468 416 374 340 312 288 267
*Models rated at 82% thermal efficiency
BTN199C Models are available for sale in California only.
All dimensions are in inches.
+BTN120 is approved for 5” vent using a 6x5 reducer.