the authority having jurisdiction, must be provided with a low water cutoff device either as a part of the boiler or at the time of boiler installation.

WARNING

UNDER NO CIRCUMSTANCES SHOULD THE EQUIPMENT ROOM WHERE THE BOILER IS INSTALLED EVER BE UNDER NEGATIVE PRESSURE. PARTICULAR CARE MUST BE TAKEN WHEN EXHAUST FANS, COMPRESSORS, AIR HANDLING EQUIPMENT, ETC., MAY INTERFERE WITH THE COMBUSTION AND VENTILATION AIR SUPPLIES OF THIS BOILER.

CHEMICAL VAPOR CORROSION

Heat exchanger corrosion and component failure can be caused by the heating and breakdown of airborne chemical vapors. Spray can propellants, cleaning solvents, refrigerator and air conditioning refrigerants, swimming pool chemicals, calcium and sodium chloride, waxes, and process chemicals are typical compounds which are corrosive. These materials are corrosive at very low concentration levels with little or no odor to reveal their presence.

Products of this sort should not be stored near the boiler. Also, air which is brought in contact with the boiler should not contain any of these chemicals. If necessary, uncontaminated air should be obtained from remote or outside sources. Failure to observe this

requirement will void the warranty.

INSTALLATION CLEARANCES

Sufficient area should be provided at the front and sides of the unit for proper servicing. For ease of service, minimum clearances of 24" (61.0 cm) in the front and 18" (46.0 cm) on the sides are recommended. It is important that the minimum clearances be observed to allow service to the control box and other controls. Observing proper clearances will allow service to be performed without movement or removal of the boiler from its installed location. Failure to observe minimum clearances may require removal of the boiler in order to service such items as the heat exchanger and burners. In a utility room installation, the door shall be wide enough to allow the boiler to enter or to permit the replacement of another appliance.

Two inch (5.1 cm) clearance is allowable from combustible construction to hot water pipes. Sufficient clearance should be provided at one end of the boiler to permit access to heat exchanger tubes for cleaning.

Access to control box items such as the Central Control Board, Flame Control Boards, Power Distribution Board and wiring harnesses is provided through a panel on the left side of the unit. A minimum service clearance of 18" (46.0 cm) is required.

These boilers are approved for installation on noncombustible flooring in an alcove with minimum clearance to combustibles of: 3 inches (7.6 cm) Right Side, and Back; 6 inches (15.2 cm) Top; Front, Alcove; 12 inches (30.5 cm) Left Side; and 6 inches (15.2 cm) surrounding the Vent.

For installation on combustible flooring use the Combustible Floor Kit. The combustible floor kit base adds 4" (10.1 cm) to the overall height of the boiler. See Figure 3.

 

 

MODEL

COMBUSTIBLE BASE KIT NUMBER

G(B,W) - 1000

211093

G(B,W) - 1300

211093-1

G(B,W) - 1500

211093-2

G(B,W) - 1850

211093-3

G(B,W) - 2100

211093-4

G(B,W) - 2500

211093-5

Figure 3. Boiler on Combustible Floor Base and Kit Numbers.

LEVELLING

Each unit must be checked after installation to be certain that it is level.

AIR REQUIREMENTS

WARNING

FOR SAFE OPERATION, AN AMPLE SUPPLY OF AIR MUST BE PROVIDED FOR PROPER COMBUSTION AND VENTILATION IN ACCORDANCE WITH THE NATIONAL FUEL GAS CODE, ANSI Z223.1 OR CAN/CSA-B149.1 CURRENT EDITION OR APPLICABLE PROVISIONS OF THE LOCAL BUILDING CODES. AN INSUFFICIENT SUPPLY OF AIR MAY RESULT IN A YELLOW, LUMINOUS BURNER FLAME, CARBONING OR SOOTING OF THE FINNED HEAT EXCHANGER, OR CREATE A RISK OF ASPHYXIATION. DO NOT OBSTRUCT THE FLOW OF COMBUSTION AND VENTILATION AIR.

UNCONFINED SPACE

In buildings of conventional frame, brick or stone construction, unconfined spaces may provide adequate air for combustion.

If the unconfined space is within a building of tight construction (buildings using the following construction: weather stripping, heavy insulation, caulking, vapor barrier, etc.), air for combustion, ventilation, must be obtained from outdoors or spaces freely communicating with the outdoors. The installation instructions for confined spaces in tightly constructed buildings must be followed to ensure adequate air supply.

CONFINED SPACE

(a) U. S. INSTALLATIONS

When drawing combustion and dilution air from inside a conventionally constructed building to a confined space, such a space shall be provided with two permanent openings, ONE WITHIN 12 INCHES OF THE ENCLOSURE TOP AND ONE WITHIN 12 INCHES OF THE ENCLOSURE BOTTOM. Each opening shall have a free area of at least one square inch per 1000 Btu/hr (22 cm2/k W) of the total input of all appliances in the enclosure.

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A.O. Smith 401, 400, 402 Chemical Vapor Corrosion, Installation Clearances, Levelling, AIR Requirements, Unconfined Space