28
CL3
Series
3.0
Installation
•
Horizontal Venting (Category III)
Horizontal Venting (Category III)
An appliance that operates with a positive vent static pressure and with a vent gas temperature that
avoids excessive condensate production in the vent is said to be “Category III”. The CL3 series
heater is considered a Category III appliance if the venting system meets all of the following criteria:
• The vent system terminates horizontally (sideways).
• The vent terminates vertically, but the length of the horizontal portion of the vent run exceeds
75% of the vertical rise length. (e.g.- If the vertical vent height is 10 feet, the horizontal run is
greater than 7 1/2 feet).
• The vent terminates below 5 feet of the vent connection on the unit.
• Horizontal venting sections of the vent pipe must be installed with a downward slope from the
appliance at a pitch of 1/4 inch per foot.
Vent enclosed spaces and buildings according to the guidelines in this manual and applicable
national, state, provincial, and local codes.
The venting system must be provided by the installer and should be comprised of single-wall
venting materials with a thickness of no less than 26 gauge. All joints must be sealed with a high
temperature silicone sealant approved for at least 550°F using a minimum bead of 1/4” x 1/4”, and
fastened with at least three corrosion resistant #8 sheet metal screws evenly spaced.
One continuous section of double-wall B vent or Duravent PVP vent may be used to pass through a
combustible wall or barrier, or the installer may continue to use single-wall vent provided a
combustible wall thimble is used which provides adequate clearances to combustibles.
All horizontal Category III vents must be terminated with a Simpson-Duravent sidewall vent cap (P/N:
SWD-4 for 4” venting).
IMPORTANT!
Once all silicone sealant has fully cured according to manufacturer’s instructions, the
installer must perform a leak test on the complete venting system. A solution of soap and water
may be used to test the venting inside the occupied space. Once the installer has verified the
venting system is completely sealed and free of leaks, the heater may be placed into operation.
