Operating instructions
11
FIGURE 4-1 Clearance to Combustible Materials
4.1 Boiler Location Considerations
• Ambient room temperature always above 32°F (0°C) to 
prevent freezing of liquid condensate. 
• Approved for installation in closets.
• Protect gas ignition system components from water 
(dripping, spraying, rain, etc.) during operation and 
service (circulator replacement, condensate trap, control 
replacement, etc.).
• Wall mount only. 
• Access to outdoors to meet minimum and maximum 
pipe lengths for combustion air and vent piping. See 
section 6.
• Disposal of condensate. See section 6.
• Drainage of water (or water - antifreeze solution) during 
boiler service or from safety relief valve discharge. See 
section 5.
• Access to system water piping, gas supply, and electrical 
service. See sections 5, 7 and 8.
• Clearances to combustible materials and service 
clearances. See Table 2 and gure 4-1.
• Multiple Boilers can be wall mounted, placed side by 
side, or back to back.
TABLE 2: BOILER CLEARANCES
Dimension
Combustible 
Materials 
(1)
Service
(1)(2)
Model
050/075/100/
150/200/299
050/075/100/
150/200/299
Top (A)
0" (0 cm) 14" (36 cm)
Left Side (B)
0" (0 cm) 0" (0 cm)
Right Side (C)
0" (0 cm) 0" (0 cm)
Front (D)
0" (0 cm)  6" (16 cm)
Back (E)
0" (0 cm) 0" (0 cm)
Bottom (F)
0" (0 cm) 12" (32 cm) 
Combustion  Air/Vent 
piping
0" (0 cm)
6" (16 cm)
Hot Water Piping
See local code 6" (16 cm)
(1)
 Required distances measured from boiler jacket.
(2)
 Service, proper operation clearance recommendation.
A
E
E
D
A
C
B
A
FLOOR
FLOOR
F
F
F
F
4 - LOCATING BOILER










