Goodman Mfg GCH9 Product Design, General Operation, Location Considerations, High Altitude Derate

PRODUCT DESIGN

General Operation

The GCH9 furnaces are equipped with an electronic ignition device used to light the burners and an induced draft blower to exhaust combustion products.

An interlock switch prevents furnace operation if the blower door is not in place. Keep the blower access door in place except for inspection and maintenance.

This furnace is also equipped with a self-diagnosing elec- tronic control module. In the event a furnace component is not operating properly, the control module LED will flash on and off in a factory-programmed sequence, depending on the problem encountered. This light can be viewed through the observation window in the blower access door. Refer to the Troubleshooting Chart for further explanation of the LED codes and Abnormal Operation - Integrated Ignition Control section in the Service Instructions for an explanation of the possible problem.

The rated heating capacity of the furnace should be greater than or equal to the total heat loss of the area to be heated. The total heat loss should be calculated by an approved method or in accordance with “ASHRAE Guide” or “Manual J-Load Calculations” published by the Air Conditioning Con- tractors of America.

*Obtain from: American National Standards Institute 1430 Broadway New York, NY 10018

Location Considerations

•The furnace should be as centralized as is practical with respect to the air distribution system.

•Do not install the furnace directly on carpeting, tile, or combustible material other than wood flooring.

•When suspending the furnace from rafters or joists, use 3/8" threaded rod and 2” x 2” x 3/8” angle as shown in the Installation and Service Instructions. The length of the rod will depend on the application and clearance necessary.

•When installed in a residential garage, the furnace must be positioned so the burners and ignition source are located not less than 18 inches (457 mm) above the floor and protected from physical damage by ve- hicles.

Notes:

1.Installer must supply one or two PVC pipes: one for com- bustion air (optional) and one for the flue outlet (required). Vent pipe must be either 2” or 3” in diameter, depending upon furnace input, number of elbows, length of run and installation (1 or 2 pipes). The optional Combustion Air Pipe is dependent on installation/code requirements and must be 2” or 3” diameter PVC.

2.Line voltage wiring can enter through the right or left side of the furnace. Low voltage wiring can enter through the right or left side of furnace.

3.Conversion kits for high altitude natural or propane gas operation are available. See High Altitude Derate chart for details.

4.Installer must supply the following gas line fittings, de- pending on which entrance is used:

Left -- Two 90º Elbows, one close nipple, straight pipe. Right -- Straight pipe to reach gas valve.

Accessibility Clearances (Minimum)

MINIMUM CLEARANCES TO COMBUSTIBLE MATERIALS

(INCHES)

POSITION*		FRONT	SIDES	REAR	TOP	FLUE	FLOOR
	Upflow	3	0	0	1	0	C
Horizontal		3	6	0	6	0	C
*=	All positioning is determined as installed unit is viewed from the front.
C=	If placed on combustible floor, floor MUST be wood only.

NC= For instalaltion on non-combustible floors only. A non-combustible subbase must be used for installations on combustible flooring.

24" at front is required for servicing or cleaning.

Note: In all cases accessibility clearance shall take prece- dence over clearances from the enclosure where accessibil- ity clearances are greater. All dimensions are given in inches.

High Altitude Derate

When this furnace is installed at high altitude, the appropri- ate High Altitude orifice kit must be installed. This is re- quired due to the natural reduction in the density of both the gas fuel and combustion air as altitude increases. The kit will provide the proper design certified input rate within the specified altitude range.

P RO P ANE AND HIG H AL T IT UDE KIT S

M O DEL	0 to	7 ,0 0 1 to	9 ,0 0 1 to	7 ,0 0 1 to	7 ,0 0 1 to
NUM BER	7 ,0 0 0 ft.	9 ,0 0 0 ft.	1 1 ,0 0 0 ft.	1 1 ,0 0 0 ft.	1 1 ,0 0 0 ft.
	LP M -0 3 1
	LP M -0 5 1	HANG1 1	HANG1 2	HALP 1 0
GCH9 * *** *X A*	LP M -0 6 2	H ig h Altitu d e	H ig h Altitu d e	H ig h Altitu d e	TBD
	P ro p a n e	N a tu ra l Ga s K it	N a tu ra l G a s K it	L P G a s K it
	C o n ve rs io n K it	(# 4 4 O rifice s )	(# 4 5 O rifice s )	(# 5 6 O rifice s )
	(# 5 5 O rific e s )

1 LP M -0 3 / LP M -0 5 s upports W hite -Rodge r s 2 -s ta ge va lve s only

2LP M -0 6 s upports Hone yw e ll a nd W hite -Rodge r s 2 s ta ge va lve s

High altitude kits are purchased according to the installa- tion altitude and usage of either natural or propane gas. Refer to the chart above for a tabular listing of appropriate altitude ranges and corresponding manufacturer’s high altitude Natu- ral Gas and Propane Gas kits. For a tabular listing of appro- priate altitude ranges and corresponding manufacturer's High Altitude Pressure Switch kits, refer to either the Pressure Switch Trip Points & Usage Chart in this manual or the Ac- cessory Charts in Service Instructions.

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