Operating instructions
21
6.1 General
This boiler requires a dedicated direct vent system. 
Install combustion air and vent piping in accordance 
with these instructions, authority having jurisdiction, 
and: 
• USA - National Fuel Gas Code, ANSI 223.1/NFPA 54.
• Canada - Natural Gas and Propane Installation Code, 
CAN/CSA B149.1
Vent connections serving appliances vented by natural draft 
shall not be connected into any portion of mechanical draft 
systems operating under positive pressure.
Install vent system in accordance with these instructions.
6.2 Removal of Existing Boiler From Common 
Vent System
When existing boiler is removed from common venting 
system, common venting system is likely to be too large for 
proper venting of appliances remaining connected to it. 
After removal of existing boiler, following steps shall 
be followed with each appliance remaining connected to 
common venting system placed in operation, while other 
appliances remaining connected to common venting system 
are not in operation:
• Seal any unused openings in common venting system.
• Visually inspect venting system for proper size and 
horizontal pitch. Determine there is no blockage or 
restrictions, leakage, corrosion and other deciencies 
which could cause an unsafe condition.
• When practical, close all building doors, windows, and 
all doors between space in which appliances remaining 
connected to common venting system are located 
and other spaces of building. Turn on clothes dryer 
and any appliance not connected to common venting 
system. Turn on exhaust fans, such as range hoods and 
bathroom exhaust so they will operate at maximum 
speed. Do not operate summer exhaust fan. Close 
replace dampers.
• Turn on appliance being inspected. Follow lighting 
instructions. Adjust thermostat so appliances will operate 
continuously.
• Test for spillage at draft hood relief opening after 5 
minutes of main burner operation. Use ame of match or 
candle, smoke from cigarette, cigar or pipe.
• Determine each appliance remaining connected to 
common venting system properly vents when tested 
as outlined above. Then return doors, windows, 
exhaust fans and any other gas-burning appliance to 
their previous condition of use.
• Any improper operation of common venting system 
should be corrected so installation conforms with National 
Fuel Code, ANSI Z223.1/NFPA 54 and/or Natural Gas 
and Propane Installation Code, CAN/CSA B149.1. 
When re-sizing any portion of common venting system, 
common venting system should be re-sized to approach  
minimum size as determined using appropriate tables in 
Chapter 13 of the National Fuel Gas Code, ANSI Z223.1/
NFPA 54 and/or Natural Gas and Propane Installation 
Code, CAN/CSA B149.1.
6.3 Venting Materials 
• See Table 4
Table 4 - Combustion air and vent pipe ttings 
must conform with the following:
Item Material  Standards
Vent Pipe 
and Fittings
PVC schedule 40 ANSI/ASTM D1785
PVC - DWV ANSI/ASTM D2665
CPVC schedule 40
ANSI/ASTM D1784/
F441
SDR-21 & SDR-26 PVC ANSI/ASTM D2241
ABS-DWV ANSI/ASTM D2661
Schedule 40ABS ANSI/ASTM F628
PP (Polypropylene)
Pipe and Components
UL 1738
ULC S636-08
Pipe 
Cement/
Primer
PVC  ANSI/ASTM D2564
CPVC ANSI/ASTM F493
Schedule 40 ABS ANSI/ASTM D2235
• IPEX is approved vent manufacturer in Canada listed 
to ULC-S636.
• IPEX System 636 Cements and Primers are approved 
in Canada listed to ULC-S636.
Use of cellular core PVC (ASTM F891), cellular core CPVC, or Radel
® 
,
(Polyphenolsulfone) in venting systems shall be prohibited.
WARNING
Use of cellular core PVC for venting ue gas could 
result in death, or serious injury.
! 
6 - COMBUSTION AIR AND VENT PIPING
WARNING
Covering non-metallic vent pipe and ttings with 
thermal insulation shall be prohibited.
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