UDX Venting Instructions

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CP-UBX-UDX-VENT (03-21) 1034631-0
GENERAL INFORMATION—CONTINUED
Venting Requirements—Continued
Venting must be in accordance with local codes and with the National Fuel Gas Code Z223.1 or CAN/CSA B149.1
and B149.2, Installation Code for Gas Burning Appliances and Equipment. Local requirements supersede national
requirements.
⚠ CAUTION ⚠
When an existing appliance is removed or replaced in a venting system, verify that the venting
system is properly sized to vent the new appliance. An improperly sized venting system may
result in the formation of condensate, leakage, and/or spillage.
Do not intermix different vent system parts from different manufacturers in the same venting
system.
Do not vent into an existing gravity vent or chimney.
Venter (Flue) Outlet Diameter
Depending on the size of vent pipe, either attach the vent pipe directly to the collar or to a taper-type connector.
For category I vent pipe, attach a 4-inch appliance adapter (available from the category I pipe manufacturer) directly
to the collar and then use a reducer if using 3-inch pipe.
For category III vent pipe, attach a 4-inch appliance adapter (available from the category III pipe manufacturer)
directly to the collar and then then use a reducer if using 3-inch pipe.
Refer to Table 1 for venter (flue) outlet diameters.
Vent System Sealing
Vent system joints depend on the type of pipe being used:
Category III pipe: follow manufacturer’s instructions for joining pipe sections—connect venter outlet or the vent
cap using secure, sealed joints that follow a procedure best suited o the style of Category III pipe being used.
Single-wall galvanized pipe (26-gauge or heavier): secure slip-fit connections using sheet metal screws or
rivets—seal all joints and seams inside the building using aluminum tape or silicone sealant.
Double-wall type B vent pipe: join pipe sections in accordance with the pipe manufacturer’s requirement—refer
to the illustrated instructions in APPENDIX A to connect double-wall pipe to the heater collar, single-wall pipe,
and vent cap.
Table 1. Venter (Flue) Outlet Diameter
Unit Size
030–125 150–250 300, 350, 400
Inches (mm)
4 (102) 5 (127 6 (152)
Vent System Support Requirements
Support horizontal runs every six feet (1.8 meters).
Support vertical runs—of type B double-wall, category I, or category III vent pipe—in accordance with the pipe
manufacturer’s requirements.
Support vertical single-wall pipe in accordance with accepted industry practice.
⚠ CAUTION ⚠
Do not rely on the heater to support either horizontal or vertical vent pipe.
Use non-combustible supports on vent pipe.