Bock Water heaters OT300-A Installation And Operation Instruction Manual page 15

SECTION IV: INSTALLATION (cont.)
VENT & COMBUSTION AIR INTAKE (cont.)
After the assembly is properly mounted to the exhaust pipe, apply more silicone caulk
between the PVC fitting and metal exhaust pipe. Caulk all the way around the pipe. If a
proper seal is not made, combustion gas will leak into the room and condensate will
collect on the floor.
The condensate trap/drain portion of the assembly is shown in Figure 5. This section
includes a 1/2" hose barb fitting for attachment of a flexible condensate hose and a 3/4"
threaded plug that can be removed for cleaning the trap. The condensate drain line must
slope down, 1/8" per foot, away from the water heater towards the drain. If there is
insufficient clearance between the condensate line connection on the water heater to
maintain downward pitch up to the drain, the heater may need to be installed several
inches above the floor on a concrete slab or use a low profile condensate pump to
facilitate drainage.
If flexible tubing is not acceptable for the condensate drain line, a rigid line assembled
from PVC Schedule 40 can be used. The supplied 1/2" hose barb fitting shall be discon-
nected and replaced with a 1/2" NPT end x 1/2" socket end adapter. The rigid line shall be
braced with floor mounted standoffs every three feet. Maintain a downward pitch of 1/8"
per foot to the drain.
Some installations require the use of a condensate neutralizer kit to reduce the acidity of
the condensate prior to reaching the drain. Figure 6 shows the connection of a rigid
condensate line to a neutralizer.
Before connecting the vent piping to the condensate elbow assembly, the condensate trap
must be primed with water. Fill the trap to the point where water starts to flow down the
condensate drain line. See Figure 5 for the minimum fill level for priming the trap.
Failure to prime the condensate trap with water will result in combustion gas (which
may contain carbon monoxide) entering the room. To avoid the risk of asphyxiation
from carbon monoxide, never operate the water heater unless the condensate trap is
sealed with water.
Figure 6: Condensate Neutralizer
! DANGER
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