Instruction manual
26
VENT AND AIR PIPE INSTALLATION
1.  Measure from the boiler level to vent. Refer to the Table 14 
on Page 36 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  ttings  using  a  clean  dry  rag. 
(Moisture  will  retard  curing  and  dirt  or  grease  will  prevent 
adhesion.)
4.  Dry t vent or air piping to ensure proper t before assembling 
any joint. The pipe should  go  a third to  two-thirds  into  the 
tting to ensure proper sealing after cement is applied. 
5.  Priming and Cementing:
•  Handle pipes and ttings carefully to prevent 
contamination of surfaces. 
•  Apply an even coat of primer to the tting 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 tting socket. 
•  While primer is still wet, apply an even coat of approved 
cement to the pipe equal to the depth of the tting 
socket. 
•  While primer is still wet, apply an even coat of approved 
cement to the tting socket. 
•  Apply a second coat of cement to the pipe. 
•  While the cement is still wet, insert the pipe into the 
tting, if possible twist the pipe a 1/4 turn as you insert it. 
Note: If voids are present, sufcient 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  ue 
gas recirculation, spillage of ue 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
•  AL 29-4C
An  adapter  is  provided  for  transition  between  the  air  inlet 
connection on the boiler and the plastic air inlet pipe. 
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 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, 
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 certied 
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 ue 
outlet must be readily accessible for visual inspection.
3.  The  components  of  the  certied  vent  system  must  not  be 
interchanged  with  other  vent  systems  or  unlisted  pipe/
ttings.
FIGURE 22.  PVC/CPVC VENTING WITH ADAPTER 
FIGURE 23.  PVC/CPVC VENTING - HORIZONTAL










