Download A.O. Smith 1850 Specifications

INSTALLATION
Electrical circuit boards are accessible through panels on the left end or top left of the jacket.
Blowers, blower air shutters and gas valves are accessible through the upper, front panels.
Burners, hot surface igniters and flame sensors are accessible through the lower, front panels.
Interior Clearances to Combustibles
These Genesis heaters are approved for installation on noncombustible flooring. They can be
installed in an alcove with minimum clearances to combustibles of:
Minimum Clearances to Combustibles
All Models
Water Side
Top
6" (152MM) 12" (304MM)
Blank
Side
3" (76MM)
Rear
Vent
3" (76MM) 6" (152mm)
Front
Alcove
Note: Approximately 24" is suggested as a service clearance to the front of the unit and 24" from
ends of the unit. Also, sufficient clearance on the return end (blank or pump side) is suggested to
permit access to heat exchanger tubes for cleaning.
AIR FOR COMBUSTION
1,000
BTU
Of Gas
12.5 Cu. Ft.
Of Supply
Air At
Sea Level
Requires
Complete combustion requires 10 cubic feet of air per 1000 BTUH gas input. The National
Fuel Gas Code also recommends an additional 2.5 cu.ft. of “excess” air.
The National Fuel Gas Code also specifies minimum make-up air opening sizes for various
building installations. (Ref: NFPA 54/ANSI Z223.1) . See the installation manual for
details.
In calculating the free area of a vent opening, the blocking effect of screens, louvers and grills should
be considered. Screens shall not be of a mesh smaller than ¼ inch square. If the free area is not
known, the latest edition of National Fuel Gas Code NFPA 54/ANSI Z223.1 recommends using figures
of 20-25 percent free area for wood louvers or 60-75 percent for metal grills or louvers.
A. O. Smith Water Products
Ashland City, Tennessee 2005 ©
3
Service Handbook
Training Department