Bock Water heaters OT300-A Installation And Operation Instruction Manual page 25

SECTION IV: INSTALLATION (cont.)
VENT & COMBUSTION AIR INTAKE (cont.)
Assembling Vent and Air Intake Joints
Cements and primers are highly flammable. Assemble joints in an adequately
ventilated area away from heat sources or open flames. Do not smoke.
Read cautions and warnings on material containers.
DO NOT use cement that is lumpy or thick. DO NOT thin cement.
Connections (i.e. joints) between plastic pipe and fittings must be properly sealed. This
requires that an appropriate primer (cleaner) and cement (solvent) are used for the type of
material (PVC, CPVC, ABS) that is used in the venting system. For PVC use ASTM D2564
grade cement, for CPVC use ASTM F493 grade cement, and for ABS use ASTM D2235 grade
cement. The following steps should be taken when connecting plastic pipe and fittings:
• Cut pipe square with hand saw and remove burrs from inside and outside edges.
• Clean fitting socket and pipe joint area of all dirt, grease, or moisture.
• Check dry fit. Pipe should easily go 1/3 of the way into the fitting socket.
• Liberally apply primer to inside of fitting socket and pipe joint area.
• Over the wet primer, apply a medium coat of cement to the fitting socket and pipe joint
area.
• Insert pipe into fitting with a slight twisting motion. Ensure that the pipe is bottomed
into the fitting.
• Hold pipe and fitting for 30 seconds to prevent push off.
• Wipe off excess cement. Cure time may be at least 2 hours for Ø4" pipe at 60 F. Longer
cure time is required for larger diameter pipe and/or lower temperatures.
Note: The vent and combustion air intake pipe/fittings must overlap a minimum
of 1/2 inch (1.3 cm) at each joint. DO NOT drill or punch holes in the plastic pipe
or fittings.
Optional Condensate Drain
If downward sloping (away from water heater) of the air intake piping is not possible or a
vertical direct vent arrangement is used, an optional condensate drain can be installed in
the air intake piping to prevent buildup of condensate in the air intake during standby
periods. Follow these steps to properly install the drain line:
• Turn off all electrical power to the water heater.
• Drill a 3/8" diameter mounting hole through the bottom of the 4" PVC pipe (section of
pipe shown in Figure 17). Make sure the hole is located at the absolute lowest point on
the horizontal pipe.
!
WARNING
!
CAUTION
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