Thermo Products CHX1-100N, CDX1-75N, CHX1-125N D. GENERAL REQUIREMENTS FOR VENTING CHX1/CDX1

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

Equipment must be installed in accordance with regulations of the National Board of Fire Underwriters and the National Fuel Gas Code. Authorities having jurisdiction should be consulted before installations are made.

C. REPLACING AN EXISTING FURNACE FROM A COMMON VENT

: These furnaces may not be common vented with any other appliance.

D. GENERAL REQUIREMENTS FOR VENTING CHX1/CDX1

The CHX1/CDX1 furnace venting system must be installed by a qualified service person in accordance with local codes, the National Fuel Gas Code (NFPA 54/ANSI Z223.1 or latest edition) and these instructions.

The following items and local code requirements must be followed:

1.The vent/air intake terminations outlined by Thermo Products in this manual must be used.

2.The entire vent/air intake system must be made of PVC Schedule 40 pipe.

NOTE: All CHX1/CDX1 furnaces recommended to be installed with outside combustion air.

3.The flue vent pipe and combustion air pipe must be at least as large as the exhaust vent/air intake pipe specified by Thermo Products. No reduction in size is permissible. The CHX1, CDX1-75 requires 2” Schedule 40 PVC pipe. The (CHX1, CDX1)-100 and 125 require 3” Schedule 40 PVC pipe.

4.This CHX1/CDX1 furnace shall not be common vented with any other appliance including those burning solid fuels.

5.Horizontal runs of exhaust vent pipe shall slope upward at least 1/4” per foot from the outlet of the furnace (CHX1’s) or the outlet of the drain tee (CDX1’s) to the vent termination at the outside wall. This will permit proper drainage of the condensate. Horizontal runs of inlet vent pipe shall slope downward at least 1/4” per foot from the outlet of the last elbow or last horizontal run, before exiting the wall, to the vent termination at the outside wall.

6.The vent pipe must be supported every 4 feet and at every joint to prevent pipe blockage caused by condensate trapped by a sag in the vent.

7.The maximum permissible vent length of straight pipe and number of elbows permitted for the exhaust vent and combustion air inlet is shown in Table 2. The elbows shown are in addition to the length of straight pipe permitted. When counting elbows, all elbows used in the exhaust vent or combustion air intake must be counted. This includes elbows used inside the furnace jacket and termination elbows. In addition, up to three elbows may be dropped and the vent length extended five feet for each elbow dropped.

MAXIMUM VENT LENGTH

TABLE 2

VENT SIZE		2 IN. PVC			3 IN. PVC
FURNACE	VENT	EXHAUST	COMBUSTION	VENT	EXHAUST	COMBUSTION
MODEL	LENGTH	VENT	AIR INTAKE	LENGTH	VENT	AIR INTAKE
	(FT.)	ELBOWS (NO.)	ELBOWS (NO.)	(FT.)	ELBOWS (NO.)	ELBOWS (NO.)
CHX1/CDX1-75	35	8 1, 2	7 2	-	-	-
CHX1/CDX1-100		NOT PERMITTED		35	8 1, 2	7 2
CHX1/CDX1-125		NOT PERMITTED		35	8 1, 2	7 2

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