Thermo Products CMC1-75DV3N, CMC1-50DV3N, CMC1-50D36N, CMC1-75D36N, CMA3-50D36N Maximum Vent Length

All installations and services must be performed by qualified service personnel.

MAXIMUM VENT LENGTH

VENT SIZE			2 IN. PVC
FURNACE	VENT	EXHAUST	COMBUSTION AIR INTAKE
MODEL	LENGTH	VENT	ELBOWS (NO.)
	(FT.)	ELBOWS
		(NO.)
CMA*/CMC*	30	8*	7**

*Note the drain elbow supplied with furnace count as 1 elbow.

**Note the two 45° elbows supplied with furnace count as 1 elbow.

Table 2

6.A hack saw may be used to cut the PVC pipe. It must be cut smoothly at right angles with all burrs removed. All joints must use standard PVC Schedule 40 elbows and couplings. Joints are not to be made by gluing, except where noted, and butting together the cut or raw edges of the vent pipe. (The joints inside the vestibule should be sealed with a silicone caulk to allow for maintenance.) Notice: Do not use silicone caulk to seal the PVC sleeve or coupling to the metal air intake collar on the burner box. The screw securing the sleeve or coupling to the collar is sufficient.

7.Use the two radiator hose clamps to connect both the exhaust vent and combustion air vent pipes to the venting system (included in the parts package.) This will aid in the serviceability of the vent should it need to be removed in the future. (Refer to figure 6).

8.Vent connections shall be checked for leakage with the furnace induced draft blower running and with the vent termination blocked. A mild soap and water solution may be used to check for leaks.

9.Vent pipe passing through an unheated space must be insulated with 1.0” thick foil faced fiberglass insulation or its equivalent to prevent freezing of any condensate within the pipe.

10.Minimum clearance from the PVC pipe to combustible material is zero inches.

IMPORTANT: The CMA/CMC furnace models are vented through the roof. For roof venting refer to Section IV, J, of this manual.

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