National Products Series B, BW3 Gas-Fired Hot Water Boilers, → Locating the Boiler, Ð4Ð

		A	1 1⁄4″ SUPPLY	4
			COMBINATION	23 1⁄″
RELIEF				VENT
	TEMP		LIMIT & RELAY
VALVE	PRESSURE		CONTROL	CONNECTOR
	GAGE		1 1⁄4″ RETURN
				BLOWER
	29″		25 1⁄4″
			23″	PRESSURE
	5 5⁄8″		5 5⁄8″	SWITCH
BURNER	1	3⁄″		CIRCULATOR
			GAS	INT. PILOT
		4
		7″	VALVE	CONTROL
LEFT SIDE		FRONT	RIGHT SIDE

						A85084
		Gas-Fired Hot Water Boilers
		NATURAL AND PROPANE GAS²			DIMENSIONS (IN.)
BOILER MODEL NUMBER*	NO. OF	A.G.A.	Heating	Net	Width	Vent Diameter
				I=B=R
	SECTIONS	Input	Capacity			To Chimney
				Rating	A
		MBH	MBH
				MBH		(Category I)
BW3AAN000042ABAA	2	42.5	36	31	11	4
BW3AAN000075ABAA	3	75.0	63	55	14-1/4	4
BW3AAN000112ABAA	4	112.5	94	82	17-1/2	4
BW3AAN000150ABAA	5	150.0	125	109	20-3/4	4
BW3AAN000187ABAA	6	187.5	155	135	24	4
BW3AAN000225ABAA	7	225.0	186	162	27-1/4	4

*Sixth position of Model No. indicates natural or propane gas usage: N = Natural Gas P = Propane Gas

²Boilers are equipped for altitudes up to 2000 ft only.

U.S.A OnlyÐFor altitudes above 2000 ft, ratings should be reduced at the rate of 4 percent for each 1000 ft above sea level.

Canada OnlyÐBoilers may be used at high altitude by using a certified field conversion kit, resulting in 10 percent derate.

Heating Capacity is based on Department of Energy (DOE) test procedure.

MBHÐ1000 Btuh (British Thermal Unit Per Hr)

Fig. 1ÐDimensional Drawing and Boiler Ratings and Capacities

Canada OnlyÐFor altitudes in the range of 2000-4500 ft above sea level, boilers may be field equipped for use at high altitude by using a certified field conversion kit. The change in main burner orifice size results in boiler's input rating being reduced by 10 percent. The conversion shall be carried out by a manufacturer's authorized representative in accordance with the requirements of manufacturer, provincial or territorial authorities having jurisdiction, and in accordance with the requirements of the CAN/CGA-B149.1 and CAN/CGA-B149.2 Installation Codes. The certified field conversion kit includes a conversion data plate which must be attached to boiler adjacent to rating plate indicating that boiler has been converted for high-altitude use. The conversion data plate must be filled in with the correct conversion information.

→LOCATING THE BOILER

NOTE: This unit MUST be set on a concrete or other non-combustible material base or floor.

1.Select level location as centralized with piping system and as near chimney as possible.

2.Place crated boiler at selected location. Remove crate by pulling crate sides from top and bottom boards. When boiler is to be installed on a combustible floor, a combustible floor base must be used.

This boiler must NOT be installed on carpeting.

3.Boiler is to be level. Metal shims may be used under base legs for final leveling.

4.The floor supporting boiler must be non-combustible. If it is combustible, place the boiler on a factory-approved combustible floor base. We use a 2-in. Cladlite™ pad as a combustible floor base. These are available from your local supplier. Use a minimum 24-in. X 30-in. pad for 2-5 section boilers and a minimum 30-in. X 30-in. pad for 6-7 section boilers. The boiler must be centered on combustible floor base.

5.Additional clearances for service may exceed clearances for fire protection. Always comply with the minimum fire protection clearances shown on the unit. An 18-inch clearance should be maintained on any side where passage is required to access another side for cleaning, servicing, inspecting or replacement of any part that may need attention. An 18-inch clearance is recommended on the control side for servicing.

6.Determine boiler room size. Rooms that are large in comparison with the size of boiler are defined as rooms having a volume equal to or greater than 16 times the volume of the boiler. Where room ceiling height is greater than 8 ft, volume of room shall be figured on the basis of 8 ft ceiling height. Determination of room size should be based on total volume of all gas fired equipment installed in that room. (See Table 1.) Refer to Section 6.3 of NFGC, Central Heating Boilers and Furnaces for further information, including approved methods for reducing clearances in large rooms.

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