Goodman Mfg RT6621031r2, GMS8 33-3/8 GAS FURNACE UNITS Product Design, General Operation

PRODUCT DESIGN

General Operation

The GMS8 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 inner blower door is not in place. Keep the blower access door in place except for inspection and maintenance. (See illustra- tion on pages 5 and 6.)

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 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:

WARNING

TO PREVENT POSSIBLE PERSONAL INJURY OR DEATH DUE TO ASPHYXIATION, THIS FURNACE MUST BE CATEGORY I VENTED. DO NOT VENT USING CATEGORY III VENTING.

Category I Venting is venting at a non-positive pressure. A furnace vented as Category I is considered a fan-assisted appliance and the vent system does not have to be “gas tight.” NOTE: Single stage gas furnaces with induced draft blowers draw products of combustion through a heat ex- changer allowing, in some instances, common venting with natural draft appliances (i.e. water heaters). All installations must be vented in accordance with National Fuel Gas Code

NFPA 54/ANSI Z223.1 - latest edition. In Canada, the fur- naces must be vented in accordance with the National Stan- dard of Canada, CAN/CSA B149.1 and CAN/CSA B149.2 - latest editions and amendments.

NOTE: The vertical height of the Category I venting system must be at least as great as the horizontal length of the venting system.

Accessibility Clearances (Minimum)

Unobstructed front clearanace of 24" for servicing is rec- ommended.

MINIMUM CLEARANCE TO COMBUSTIBLE MATERIALS - INCHES

Sides	Rear	Front*		Vent		Top
			SW		B
1	0	3	6		1	1

*24" clearnace for serviceability recommended.

**Single Wall Vent (SW) to be used only as a conncetor.

Refer to the venting tables outlined in the Installation Manual for additional venting requirements.

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

IMPORTANT NOTE: The furnace as shipped requires no change to run between 0 - 5500 feet. Do not attempt to increase the firing rate by changing orifices or increasing the manifold pressure below 5500 feet. This can cause poor combustion and equipment failure.

High altitude installations above 5500 feet may require both a pressure switch and an orifice change. These changes are necessary to compensate for the natural reduction in the density of both the gas fuel and the combustion air at higher altitude.

For installations above 5500 feet, please refer to your dis- tributor for required kit(s). Contact the distributor for a tabu- lar listing of appropriate manufacturer’s kits for propane gas and/or high altitude installations. The indicated kits must be used to insure safe and proper furnace operation. All conver- sions must be performed by a qualified installer, or service agency.

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