Thermo Pride Gas/Propane Furnace Concentric Vent (CMA) - Manual (Page 3)

ALL INSTALLATIONS AND SERVICE MUST BE PERFORMED BY QUALIFIED SERVICE PERSONNEL.
INSTALLING CONCENTRIC VENT UTILIZING EXISTING ROOF JACK AS A CHASE.
1. Required kit: AOPS7483
2. Type installation: Vertical through the roof
3. Remove top cap and bird screen from roof jack. If present, remove 4” diameter inner
pipe shield and fold over vertical tabs inside flue pipe.
4. Determine vertical height dimension (DIM-A) of current roof jack, see FIG-2. THIS
DIMENSION IS IMPORTANT. If this dimension is less than 14-7/8”, skip to step 6. If
dimension is greater than 14-7/8”, the 3” and 2” PVC pipes in the concentric vent
assembly will need to be replaced with longer pipes to ensure proper installation.
5. To extend the concentric vent assembly, the two pipes supplied in the kit will need to be
replaced with single piece (no coupling connections allowed) same diameter solid core,
field supplied SDR-26 PVC (ASTM D2241) pipe. See FIG-1, FIG-3 & FIG-4 for
calculating new pipe cut lengths.
UNIT OPERATION HAZARD.
Failure to follow this caution may result in intermittent unit operation.
Do not use field supplied couplings to extend the pipes. Airflow restriction will occur and the
furnace pressure switch may cause intermittent operation.
6. Place Fernco Fitting on end of 3” pipe leaving 1 ¼” of pipe exposed above fitting for rain
cap, see FIG-3. Tighten clamp.
7. Affix rain cap to 2” pipe with either PVC cement or a field supplied stainless steel screw,
see FIG-4.
CARBON MONOXIDE POISONING, FIRE AND EXPLOSION HAZARD.
Failure to follow this warning could result in death, personal injury and/or property damage.
When using the alternate screw assembly method, drill a clearance hole in the rain cap and a
pilot hole in the vent pipe for screw size being used. Failure to drill adequate holes cause
cracking o the PVC components, allowing flue gasses to be recirculated.
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