Bradford White M-I-MS40T6LX User Manual
Page 10

10
Combustion Air Supply
All combustion air must be supplied from outdoors by one of the following 
installation methods and as illustrated in Figure 5. The flow of combustion and 
ventilating air must not be obstructed. Adequate air must be supplied for 
combustion and ventilation. An insufficient supply of air will cause recirculation 
of combustion products resulting in air contamination that may be hazardous to 
life. Such a condition often will result in a yellow, luminous burner flame, 
causing carboning or sooting of the combustion chamber, burners and flue 
tubes with possible damage to the heater. 
AIR INTAKE INSTALLATION -
3” (7.6cm) diameter telescoping air intake and
leg enclosure are required to supply fresh air to the water heater for 
combustion kit P/N 239-37025-01 for 30 gallon (113.5L) water heaters and 239-
37025-02 for 40 gallon (151.4L) water heaters. Note: When a mobile home is 
tightly skirted, an air inlet opening in the skirting must be provided. The 
opening shall have a minimum free area of at least 9 in
2
(22.9cm
2
). If the
opening is screened or covered with a louver, the total free area must be 
at least 9 in
2
(22.9cm
2
).
The following steps must be followed for proper
installation of these air supply components: (Refer to Figure 5).
