Bosch GWH 345 ESR-N Manual page 18

Installation instructions
3.6.5 Vertical terminations
Caution: Failure
condensate drain may result in damage
not covered by the manufacturer's
warranty. See
approved vent terminator must be used.
See Table 5 for known approved
vertical vent terminations.
Horizontal runs
Any gas vent section that is greater than 45 degrees
from the vertical is considered horizontal. Horizontal
sections must slope upwards from heater at least ¼
inch for every foot of its horizontal length and be
properly supported. Exception: after last elbow in vent
run, pitch horizontal pipe and termination to the outside
1/4" per foot to prevent rain water from entering the
pipe.
Vent terminations
The exhaust vent must terminate above the roof surface
with an approved vent cap not less than 2 feet (0.6 m)
above the highest point where it passes through the
roof and at least 2 feet (0.6 m) higher than any vertical
wall or similar obstruction within 10 feet (3.1m). See
Fig. 21.
Fig. 21 Vertical vent termination clearances
Interior masonry chimneys
The single wall stainless steel exhaust vent pipe must
be permanently mounted inside the masonry chimney.
The masonry chimney may have to be tile or metal lined
before the insertion of the gas vent pipe; check local
codes for clarification.
You may not vent any other fuel burning appliances into
any free space remaining in the chimney. The vent
terminator must extend at least 3 feet (0.9 m) above
where the chimney meets the roofline and at least 2 feet
(0.6 m) higher than any vertical wall or similar
obstruction within 10 feet (3.1 m). The top of the
chimney must be sealed to prevent rain water or other
elements from entering the chimney.
18
to install a
chapter 3.6.3. An
Exterior Masonry Chimney
Refer to the National Fuel Gas Code and consult a local
venting HVAC contractor. Not recommended in cold
climates.
3.6.6 Horizontal terminations
Warning: After last elbow in vent run,
pitch horizontal pipe and termination to
the outside 1/4" per foot to prevent rain
water from entering the pipe.
An approved vent terminator must be used. See Table 5
for known approved horizontal vent terminations.
Install a condensate drain if the total straight vent length
is greater than 5 feet or if the exhaust vent pipe passes
through an unconditioned space.
The exhaust termination tee must project out a minimum
of 10" and maximum of 16" on center from the wall
thimble.
Fig. 22 and table 9 show the required clearances for
the vent termination. Follow local codes if more
stringent.
6 720 607 909