A.O. Smith 3400 - Manual (Page 27)

27
VENT AND AIR PIPE INSTALLATION
1. Measure from the boiler level to vent. Refer to the Table 13
on Page 37 for the allowable lengths.
2. Prepare pipes to the required lengths and deburr the inside
and outside of the pipe ends. Chamfer outside the pipe end
to ensure even cement distribution when joining.
3. Clean all pipe ends and fittings using a clean dry rag.
(Moisture will retard curing and dirt or grease will prevent
adhesion.)
4. Dry fit vent or air piping to ensure proper fit before assembling
any joint. The pipe should go a third to two-thirds into the
fitting to ensure proper sealing after cement is applied.
5. Priming and Cementing:
• Handle pipes and fittings carefully to prevent
contamination of surfaces.
• Apply an even coat of primer to the fitting socket.
• Apply an even coat of primer to the pipe end to
approximately 1/2" beyond the socket depth.
• Apply a second primer coat to the fitting socket.
• While primer is still wet, apply an even coat of approved
cement to the pipe equal to the depth of the fitting
socket.
• While primer is still wet, apply an even coat of approved
cement to the fitting socket.
• Apply a second coat of cement to the pipe.
• While the cement is still wet, insert the pipe into the
fitting, if possible twist the pipe a 1/4 turn as you insert it.
NOTE: If voids are present, sufficient cement was not applied
and joint could be defective.
• Clear excess cement from the joint removing ring or
beads as it will needlessly soften the pipe.
When a sidewall or vertical rooftop combustion air supply system
is disconnected for any reason, the air inlet pipe must be resealed
to ensure that combustion air will be free of contaminants and
supplied in proper volume.
Failure to properly seal all joints and seams may result in flue
gas recirculation, spillage of flue products and carbon monoxide
emissions causing severe personal injury or death.
AIR INLET PIPE MATERIALS
Make sure the air inlet pipe(s) are sealed. The acceptable air
inlet pipe materials are:
• PVC/CPVC
• Polypropylene
The opening on the air intake box will readily accept PVC/CPVC
pipes. If air intake is Polypropylene, an adapter (use the ones
provided with exhaust kit) is required. Adapter part numbers:
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. Do not install seams of
vent pipe on the bottom of horizontal runs.
Secure all joints with a minimum of 3 sheet metal screws or pop
rivets. Apply Aluminum Foil Duct Tape or silicone sealant to all
screws or rivets installed in the vent pipe.
Make sure that the air inlet pipes are properly supported.
The PVC/ CPVC or Polypropylene air inlet pipe must be cleaned
and sealed with the pipe manufacturer’s recommended solvents
and standard commercial pipe cement for the material used.
The PVC/CPVC or Polypropylene air inlet pipe should use a
silicone sealant to ensure a proper seal at the boiler connection
and the air intake adapter connection. Proper sealing of the air
inlet pipe ensures that combustion air will be free of contaminants
and supplied in proper volume.
REQUIREMENTS FOR INSTALLATION IN CANADA
1. Installations must be made with a vent pipe system certified
to ULC-S636. IPEX is an approved vent manufacturer in
Canada supplying vent material listed to ULC-S636.
2. The initial 3 feet of plastic vent pipe from the appliance flue
outlet must be readily accessible for visual inspection.
3. The components of the certified vent system must not be
interchanged with other vent systems or unlisted pipe/
fittings.
SIZE PART NUMBERS
6" 324400-000
8" 324401-000
10" 324402-000