Bock Water heaters OT300-A Installation And Operation Instruction Manual page 24

SECTION IV: INSTALLATION (cont.)
VENT & COMBUSTION AIR INTAKE (cont.)
Install piping through the roof as shown in Figure 15. Adequate length of pipe must protrude
beyond the exterior of the roof (see dimension Y). Directions for cementing joints (such as the
terminal fittings to the straight pipe) can be found on page 25. Two 90 elbows are
recommended for the exhaust termination to reduce the risk of rain, snow, or foreign objects
entering the system. Install a screen inside the air intake termination fitting. Complete the
installation of the remainder of the vent system and attach to the water heater. Piping must be
sufficiently supported. At minimum, it is recommended that a support is placed along the
vent piping every 4 feet.
Page 24
Vent
Terminal
Dim Y
From
Water
Heater
Figure 15: Vertical Venting, 1-pipe termination
Figure 16: Vertical Power Vent Arrangement
Dim Y Requirements
1) Minimum 12 in. (30 cm) above roof
(US). Minimum 18 in. (46 cm) above
roof (Canada).
2) Minimum 12 in. (30 cm) above
Support
anticipated snow level (US). Minimum
Bracket
18 in. (46 cm) above anticipated snow
level (Canada).
3) Maximum 24 in. (61 cm) above roof
without additional support.