9
VENT PIPE MODIFICATION
When an existing boiler is removed from a common venting
system, the common venting system is likely to be too large for
the proper venting of the appliances remaining connected to
it. If this situation occurs, the following test procedure must be
followed:
REMOVAL OF BOILER FROM VENTING SYSTEM
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.
Seal any unused openings in the common venting system.
1.
Visually inspect the venting system for proper size and
2.
horizontal pitch and determine there is no blockage or
restriction, leakage, corrosion and other deficiencies which
could cause an unsafe condition.
Insofar as is practical, close all building doors and win-
3.
dows and all doors between the space in which the ap-
pliances 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 bathroom exhausts, so they will oper-
ate at maximum speed. Do not operate a summer exhaust
fan. Close fireplace dampers.
Place in operation the appliance being inspected. Follow
4.
the lighting instructions. Adjust thermostat so appliance
will operate continuously.
Test for spillage at the draft hood relief opening after 5
5.
minutes of main burner operation. Use the flame of a
match or candle, or smoke from a cigarette, cigar or pipe.
After it has been determined that each appliance remain-
6.
ing connected to a common venting system properly vents
when tested as outlined above, return doors, windows,
exhaust fans, fireplace dampers and any other gas burning
appliance to their previous conditions of use.
Any improper operation of the common venting system
7.
should be corrected so the installation conforms with
either the latest revision of the National Fuel Gas Code,
ANSI Z223.1, (when installed in the United States) or the
CAN1-B149.1 and/or B149.2 Installation Codes for Gas-
Burning Equipment, (when installed in Canada). 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 appendix G in the latest revision of the National
Fuel Gas Code, ANSI Z223.1 or the CAN1-B149.1 and/or
B149.2 Installation Codes for Gas-Burning Equipment.
National Excelsior Company
www.excelsiorhvac.com
Subject to change without notice.
