18
2
Venting
Installation & Service Manual
Automatic Vent Damper
This heating boiler is design certified for use with the automatic
vent damper (FIG. 2-7) part number printed on the boiler’s
rating plate. A vent damper is optional on heating boilers above
360,000 Btu/hr. Automatic vent dampers are not required or
fur nished on potable water heaters. Water heaters with inputs of
360,000 Btu/hr and less may be ordered with the vent damp er as
an option. A vent damper is a useful tool for saving energy when
installed inside the living space where air can cir cu late freely
around the appliance. The vent damper will not save as much,
if any, energy if it is installed in locations such as:
- Unheated garage
- Attic
- Crawlspace
- Mechanical room that is vented outdoors
For installation and maintenance on the vent damper, refer to
the instructions supplied with the vent damper.
Larger input heating boilers and water heaters will have a
jumper plug installed in the ter mi nal block to allow operation
without a damper. Remove the jumper plug from the terminal
block to connect an optional vent damper wire harness (water
heater shown in FIG. 2_8). The jumper plug MUST be in place
if an optional vent damper is not used on water heaters and
larger input heating boilers.
Do not install the vent damper within 6"
(152 mm) of combustible materials.
The damper position indicator must be in a visible
lo
ca
tion with access for service following in
stal
la
tion. The
damper must be in an open position when appliance main
burners are operating.
The part number for the automatic vent damper required on
this heating boiler is printed on the rating plate. Vent damper
regulations are design certified per the latest edition of ANSI
Z21.66.
VENT DAMPER
TERMINAL
BLOCK
Figure 2-7_
CB with Vent Damper and Vent Damper
Terminal Block
WARNING
The vent damper must be installed directly
on the flue outlet located on the top of the
draft hood (see FIG. 2-7). Do not alter the
wire har ness sup plied with the vent damper.
Follow the instructions supplied with the
vent damper.
CAUTION
An appliance which is shut down or will not
operate may experience freezing due to
con
vec
tive air flow down the flue pipe
connected to the unit. Proper freeze
protection must be pro
vid
ed, see
Freeze
Pro tec tion
in the Startup Section of this
manual.
DANGER
Install the vent damper to service only the
single ap pli ance for which it is intended. If
improperly installed, a hazardous
condition such as an ex plo sion or carbon
monoxide poisoning could result.
WARNING
VENT DAMPER
Figure 2-8_
CW with Vent Damper
