9
V. VENTING
Direct Vent “Direct vent” is also called “sealed combustion”. All combustion air is drawn from outside the building directly
into the boiler. The boiler vents vertically or horizontally, assisted by a fan in the boiler. Gas vent must resist temperature and
Power Vent
the boiler room without the use of a combustion air pipe.
operating under positive pressure.
A. General
When an existing boiler is removed from a common venting
system, the common venting system is likely to be too large
for proper venting of the appliances remaining to it.
At the time of removal of an existing boiler, the following
steps shall be followed with each appliance remaining
connected to the common venting system placed in
operation, while the other appliances remaining connected
to the common venting system are not in operation:
1. Seal any unused openings in the common venting
system.
size and horizontal pitch and determine there is no
blockage or restriction, leakage, corrosion, and other
3. Insofar as is practical, close all building doors and
windows and all doors between the space in which
the appliances remaining connected to the common
venting system are located and other spaces of the
building. Turn on clothes dryers and any appliance
not connected to the common venting system.
Turn on any exhaust fans, such as range hoods and
mum speed. Do not operate a summer exhaust fan.
Adjust thermostat so appliance will operate
continuously.
5. Test for spillage at the draft hood relief opening after
of a match or candle, or smoke from a cigarette,
cigar or pipe.
6. After it has been determined that each appliance
remaining connected to the common venting system
properly vents when tested as outlined above, return
any other gas burning appliance to their previous
conditions of use.
7. Any improper operation of the common venting
system should be corrected so the installation
conforms with the National Fuel Gas Code, ANSI
. When resizing any portion of
the common venting system, the common venting
system should be resized to approach the minimum
size as determined using the appropriate tables in
National Fuel Gas Code, ANSI
WARNING
Vent this boiler according to the instructions.
Failure to do so may cause products of
combustion to enter the building resulting in
severe property damage, personal injury or
death.
CAUTION
Install this boiler according to this manual and
the National Fuel Gas Code, ANSI Z223.1/NFPA
54, or applicable provisions of the local building
codes. Contact local building or re ofcials
about restrictions and installation inspection in
your area.
CAUTION
Failure to install a condensate drain line could
cause boiler to shutdown unexpectedly.
