Installation Clearances; Leveling; System Connections; Venting - A.O. Smith HW 300 Installation & Operation Manual

INSTALLATION CLEARANCES

These boilers are approved for installation on combustible flooring
in an alcove with minimum clearance to combustibles of:
HW HW
300 399
TOP 28" (711.2) 32" (812.8) 24" (609.6) 24" (609.6) 24" (609.6)
SIDES 6" (152.4) 6" (152.4) 24" (609.6) 24" (609.6) 24" (609.6)
REAR 6" (152.4) 6" (152.4) 24" (609.6) 24" (609.6) 24" (609.6)
VENT 6" (152.4) 6" (152.4)
Two inch (50.8mm) clearance is allowable from combustible
construction for hot water pipes.
VENTING THE BOILER - STANDARD VENTING
THE INSTRUCTIONS IN THIS SECTION ON VENTING
THE BOILER MUST BE FOLLOWED TO AVOID CHOKED
COMBUSTION OR RECIRCUL ATION OF FLUE GASES.
SUCH CONDITIONS CAUSE SOOTING OR RISKS OF FIRE
AND ASPHYXIATION.
TYPE B VENTING MAY BE USED WITH THESE BOILERS. ALL
LOCAL UTILITY REGULATIONS ON VENTING SHOULD BE
FOLLOWED.
For boilers for connection to gas vents or chimneys, vent sizing,
installation and termination shall be in accordance with the
TABLE 4
HW HW
420 520
6" (152.4) 6" (152.4)
A TYPICAL BOILER INSTALLATION
WARNING
Sufficient area should be provided at the front and rear of the unit
for proper servicing. Clearances of 24 inches (609.4mm) in the
rear and 48 inches (1,219mm) in the front are required by code.
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
such as a water heater.
HW
610 & 670
Each unit should be checked after installation to be certain that it is level.
If the unit is not level, insert metal shims under the legs of the unit
to correct this condition.
6" (152.4)
The system installation must conform to these instructions
and to the requirements of the local code authority having
jurisdiction. Good practice requires that all heavy piping be
supported.
FIGURE 7.

VENTING

current edition of the National Fuel Gas Code, ANSI Z223.1, or
CAN/CSA B149.1, Installation Codes, or applicable provisions
of the local building codes.
Vent connectors serving appliances vented by natural draft shall
not be connected into any portion of mechanical draft systems
operating under positive pressure.
The minimum distance from adjacent public walkways, adjacent
buildings, openable windows and building openings shall not be
less than those values specified in the National Fuel Gas Code,
ANSI Z223.1 and/or CAN/CSA B149.1, Installation Codes;
Stack or chimney must be a minimum height of 12" (305mm)
above the annual snow fall to prevent blockage.
14

LEVELING

SYSTEM CONNECTIONS