15
Installation & Operation Manual
2
General
venting
(continued)
Install vent and combustion air piping
DANGER
The Crest must be vented and supplied
with combustion and ventilation air as
described in this section. Ensure the vent
and air piping and the combustion air
supply comply with these instructions
regarding vent system, air system, and
combustion air quality. See also Section
1 of this manual.
Inspect finished vent and air piping
thoroughly to ensure all are airtight and
comply with the instructions provided
and with all requirements of applicable
codes.
Failure to provide a properly installed
vent and air system will cause severe
personal injury or death.
Air inlet pipe materials:
The air inlet pipe(s) must be sealed. Choose acceptable
combustion air inlet pipe materials from the following list:
ABS, PVC, or CPVC
Dryer Vent or Sealed Flexible Duct (not recommended
for rooftop air inlet)
Galvanized steel vent pipe with joints and seams sealed
as specified in this section.
Type “B” double-wall vent with joints and seams sealed
as specified in this section.
AL29-4C, stainless steel material to be sealed to
specification of its manufacturer.
*Plastic pipe may require an adapter (not provided) to
transition between the air inlet connection on the appliance
and the plastic air inlet pipe.
WARNING
Using vent or air intake materials other
than those specified, failure to properly
seal all seams and joints or failure to follow
vent pipe manufacturer’s instructions can
result in personal injury, death or property
damage. Mixing of venting materials will
void the warranty and certification of the
appliance.
NOTICE
The use of double-wall vent or insulated
material for the combustion air inlet
pipe is recommended in cold climates
to prevent the condensation of airborne
moisture in the incoming combustion air.
Sealing of Type “B” double-wall vent material or galvanized
vent pipe material used for air inlet piping on a sidewall or
vertical rooftop Combustion Air Supply System:
a. Seal all joints and seams of the air inlet pipe using either
Aluminum Foil Duct Tape meeting UL Standard 723 or
181A-P or a high quality UL Listed silicone sealant such
as those manufactured by Dow Corning or General
Electric.
b. Do not install seams of vent pipe on the bottom of
horizontal
runs.
c. Secure all joints with a minimum of three sheet metal
screws or pop rivets. Apply Aluminum Foil Duct Tape or
silicone sealant to all screws or rivets installed in the vent
pipe.
d. Ensure that the air inlet pipes are properly supported.
The PVC, CPVC, or ABS air inlet pipe should be cleaned and
sealed with the pipe manufacturer’s recommended solvents
and standard commercial pipe cement for the material used.
The ABS, PVC, CPVC, Dryer Vent or Flex Duct air inlet pipe
should use a silicone sealant to ensure a proper seal at the
appliance connection and the air inlet cap connection. Dryer
vent or flex duct should use a screw type clamp to seal the
vent to the appliance air inlet and the air inlet cap. Proper
sealing of the air inlet pipe ensures that combustion air will be
free of contaminants and supplied in proper volume.
