Leveling, Clearances | A.O. Smith BTN 120 THRU 400/A Series specification

length and width at least 2" greater than the diameter of the heater and must be piped to an adequate drain. The pan must not restrict combustion air flow.

LEVELING

If the unit is not level, insert the bolts which were used in crating into the legs to correct this condition.

CLEARANCES

These heaters are approved for installation on combustible flooring (with Leg Kit #6570-7) in an alcove when the minimum clearance from any combustion construction are followed as indicated in figure 5 and Table 4.

In all installations the minimum combustible clearances from vent piping shall be 6" (152mm). Vent piping passing through a combustible wall or ceiling must be a continuous run (no joints) and retain the 6" (152mm) clearance unless an approved reducing thimble is used.

A service clearance of 24" (610mm) should be maintained from serviceable parts, such as relief valves, flue baffles, thermostats, cleanout openings or drain valves.

The units are approved for installation with side, rear and ceiling clearances as indicated below:

MINIMUM CLEARANCES TO COMBUSTIBLES IN INCHES (mm)

MODEL	”A”	”B”	”C”	”D”
	RIGHT	LEFT	BACK	CEILING
	SIDE	SIDE
BTN-120	2” (51mm)	2” (51mm)	2” (51mm)	12” (305mm)
BTN-154	2” (51mm)	2” (51mm)	2” (51mm)	12” (305)
BTN-180	2” (51mm)	2” (51mm)	2” (51mm)	12” (305)
BTN-199	2” (51mm)	2” (51mm)	2” (51mm)	12” (305)
BTN-200/A	2” (51mm)	2” (51mm)	2” (51mm)	12” (305)
BTN-250/A	2” (51mm)	2” (51mm)	2” (51mm)	12” (305)
BTN-275/A	2” (51mm)	2” (51mm)	2” (51mm)	12” (305)
BTN-310/A	3” (76mm)	3” (76mm)	3” (76mm)	12” (305)
BTN-366/A	6” (152mm)	6” (152mm)	6” (152mm)	12” (305)
BTN-400/A	3” (76mm)	3” (76mm)	3” (76mm)	12” (305)

TABLE 4

CLEARANCES TO NONCOMBUSTION CONSTRUCTION

MODEL	”A”	”B”	”C”	”D”
	RIGHT	LEFT	BACK	CEILING
	SIDE	SIDE
BTN-120	0	0	0	12” (305mm)
BTN-154	0	0	0	12” (305mm)
BTN-180	0	0	0	12” (305mm)
BTN-199	0	0	0	12” (305mm)
BTN-200/A	0	0	0	12” (305mm)
BTN-250/A	0	0	0	12” (305mm)
BTN-275/A	0	0	0	12” (305mm)
BTN-310/A	6” (152mm)	6” (152mm)	6” (152mm)	12” (305mm)
BTN-366/A	0	0	0	12” (305mm)
BTN-400/A	0	0	0	12” (305mm)

TABLE 5

HARD WATER

Where hard water conditions exist, water softening or the threshold type of water treatment is recommended. This will protect the dishwashers, coffee urns, water heaters, water piping and other equipment.

See MAINTENANCE section for details of tank cleanout procedure.

AIR REQUIREMENTS

REFER TO THE LATEST EDITION OF THE "NATIONAL FUEL GAS CODE" ANSI Z223.1/NFPA 54.

KEEP APPLIANCE AREA CLEAR AND FREE OF COMBUSTIBLE MATERIALS, GASOLINE AND OTHER FLAMMABLES, VAPORS AND LIQUIDS.

DO NOT OBSTRUCT THE FLOW OF COMBUSTION OR VENTILATING AIR.

WARNING

FOR SAFE OPERATION PROVIDE ADEQUATE AIR FOR COMBUSTION AND VENTILATION. AN INSUFFICIENT SUPPLY OF AIR WILL CAUSE RECIRCULATION OF COMBUSTION PRODUCTS RESULTING IN AIR CONTAMINATION THAT MAY BE HAZARDOUS TO LIFE. SUCH A CONDITION OFTEN WILL RESULT IN AYELLOW, LUMINOUS BURNER FLAME, CAUSING CARBONING OR SOOTING OF THE COMBUSTION CHAMBER,

ILLUSTRATION OF MINIMUM COMBUSTIBLE CLEARANCES INANALCOVE - FIGURE 5