CLEARANCES

These heaters are approved for installation on combustible flooring in an alcove when the minimum clearances from any combustion construction are followed as indicated in Figure 4.

In all installations the minimum combustible clearances from any vent piping shall be 0". Vent piping passing through a combustible wall or ceiling must be a continuous run (no joints).

A service clearance of 24" (61 cm) should be maintained from serviceable parts such as relief valves, thermostats, cleanout openings, drain valves and venting connections.

Always disconnect electrical power before servicing the unit

*ILLUSTRATION OF MINIMUM COMBUSTIBLE CLEARANCES IN AN ALCOVE.

FIGURE 4.

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.

SERIOUS DAMAGE TO THE HEATER AND RISK OF FIRE OR EXPLOSION. IT CAN ALSO CREATE A RISK OF ASPHYXIATION.

UNCONFINED SPACE

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

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 and ventilation must be obtained from outdoors. The installation instructions for confined spaces in tightly constructed buildings must be followed to ensure adequate air supply.

CONFINED SPACE

When drawing combustion air from inside a conventionally constructed building to a confined space, such a space shall be provided with two permanent openings, ONE IN OR WITHIN 12 INCHES (31 cm) OF THE ENCLOSURE TOP AND ONE IN OR WITHIN 12 INCHES (31 cm) OF THE ENCLOSURE BOTTOM. Each opening shall have a free area of at least one square inch per 1000 Btuh (2,203mm2/kW) appliances in the enclosure, but not less than 100 square inches (645 cm²).

If the confined space is within a building of tight construction, air for combustion and ventilation must be obtained from outdoors. When directly communicating with the outdoors through vertical ducts, two permanent openings, located in the above manner, shall be provided. Each opening shall have a free area of not less than one square inch per 4000 Btuh (551mm2/kW) of the total input of all appliances in the enclosure. If horizontal ducts are used, each opening shall have a free area of not less than one square inch per 2000 Btuh (1,102mm2/kW) of the total input of all appliances in the enclosure.

AIR REQUIREMENTS

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

DO NOT OBSTRUCT THE FLOW OF COMBUSTION AND 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 CONTAMINATION THAT MAY BE HAZARDOUS TO LIFE. SUCH A CONDITION OFTEN WILL RESULT INAYELLOW, LUMINOUS BURNER FLAME, CAUSING CARBONING OR SOOTING OF THE COMBUSTION CHAMBER, BURNERS AND FLUE TUBES AND CREATES A RISK OF ASPHYXIATION.

CHEMICAL VAPOR CORROSION

WARNING

CORROSION OF THE FLUE WAYS AND VENT SYSTEM MAY OCCUR IF AIR FOR COMBUSTION CONTAINS CERTAIN CHEMICAL VAPORS. SUCH CORROSION MAY RESULT IN FAILURE AND RISK OF ASPHYXIATION.

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 potentially corrosive.

PRODUCTS OF THIS SORT SHOULD NOT BE STORED NEAR THE HEATER. ALSO, AIR WHICH IS BROUGHT IN CONTACT WITH THE HEATER SHOULD NOT CONTAIN ANY OF THESE CHEMICALS. IF NECESSARY, UNCONTAMINATED AIR SHOULD BE OBTAINED FROM REMOTE OR OUTSIDE SOURCES.

MECHANICAL EXHAUSTING OF ROOM AIR

Where an exhaust fan is installed in the same room with a heater, sufficient openings for air must be provided in the walls.

UNDERSIZED OPENINGS WILL CAUSE AIR TO BE DRAWN INTO THE ROOM THROUGH THE HEATER’S VENTING SYSTEM, CAUSING POOR COMBUSTION. SOOTING MAY RESULT IN

VENTING

WARNING

THE INSTRUCTIONS IN THIS SECTION ON VENTING MUST BE FOLLOWED TO AVOID CHOKED COMBUSTION OR RECIRCULATION OF FLUE GASES. SUCH CONDITIONS CAUSE SOOTING OR RISKS OF FIRE AND ASPHYXIATION.

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A.O. Smith BTH 300A, BTH 400A warranty Clearances, Hard Water, Unconfined Space, Confined Space, AIR Requirements, Venting
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BTH 300A, BTH 400A specifications

A.O. Smith has established itself as a leader in the water heating industry, offering a range of products that combine efficiency, reliability, and innovative technology. Among these products, the BTH 300A and BTH 400A models stand out for their advanced features and robust performance, catering to both residential and commercial needs.

The BTH 300A and BTH 400A are high-efficiency water heaters designed with cutting-edge condensing technology, allowing for significant energy savings compared to traditional water heating systems. These models utilize a modulating gas valve that adjusts the burner operation based on the demand for hot water. This smart system not only enhances efficiency but also ensures a consistent supply of hot water without the worry of fluctuations.

One of the standout features of the BTH series is its compact design. Both the BTH 300A and BTH 400A are engineered to fit into smaller spaces, making them ideal for properties with limited installation areas. Their lightweight construction and user-friendly installation features further simplify the process, ensuring that homeowners and professionals alike can set them up with ease.

The BTH models are equipped with advanced control systems that offer precise temperature adjustment capabilities. Users can easily customize their hot water settings to meet specific household or business requirements. This adaptability is supported by the built-in digital display, which provides real-time information about the operating status of the unit.

Safety is a key consideration in the design of the BTH 300A and BTH 400A. They feature a robust set of safety mechanisms, including temperature lockout and venting safeguards, ensuring reliable operation and peace of mind for users. A.O. Smith also understands the importance of longevity in water heaters, and these models are built with high-quality materials, making them resistant to corrosion and wear over time.

In terms of performance, both the BTH 300A and BTH 400A models deliver exceptional heating capabilities, capable of meeting high demands while maintaining efficiency. With customer satisfaction at the forefront, A.O. Smith backs these units with an extensive warranty, demonstrating their commitment to quality and long-term performance.

In summary, the A.O. Smith BTH 300A and BTH 400A water heaters exemplify the marriage of innovation and functionality. With their energy-efficient operation, customizable settings, compact design, and advanced safety features, these models are a compelling choice for those in need of reliable and effective hot water solutions.
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