Goodman GMH80904BN Series User Manual

C
US
®
RT6621014 Rev. 2
June 2009
Copyright ©2006 - 2009 Goodman Manufacturing Company, L.P.
This manual is to be used by qualified, professionally trained HVAC technicians only.
Goodman does not assume any responsibility for property damage or personal
injury due to improper service procedures or services performed by an unqualified
person.
• Refer to Service Manual RS6610004 for installation, operation, and troubleshooting information.
• All safety information must be followed as provided in the Service Manual.
• Refer to the appropriate Parts Catalog for part number information.
• Model numbers listed on page 3.
GMH8 39" 80% Gas Furnace
80% AFUE, 2-Stage (Convertible),
Multi-Speed, Upflow/Horizontal
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Goodman GMH80904BN Series Specifications

General

Brand	Goodman
Model	GMH80904BN Series
Category	Furnace
Language	English

Summary

Product Identification

Model and Manufacturing Number Usage

Usage of model and manufacturing numbers for parts and service identification.

Product Design - General Operation and Location

General Operation

Overview of the furnace's electronic ignition, induced draft blower, and control module.

Location Considerations

Guidelines for furnace placement, including clearances and installation in garages.

Product Design - Clearances and Altitude

Accessibility Clearances (Minimum)

Minimum clearances required to combustible materials for servicing and operation.

High Altitude Derate

Information on required kits and derating for furnaces installed at high altitudes.

Product Design - Switch Specifications

Pressure Switch Trip Points and Usage Chart

Tables detailing pressure switch trip points and part numbers for different models.

T.O.D. Primary Limit

Specifications for the primary limit switch, including part numbers and open settings.

Rollout Limit Switches

Specifications for rollout limit switches, including part numbers and open settings.

Auxiliary Limit Switches

Specifications for auxiliary limit switches, including part numbers and open settings.

Product Design - Coil Matches and Filters

Coil Matches

Information on Goodman brand coils compatible with GDH8 furnaces using R22 and R-410A.

Upflow Filters

Filter requirements and sizes for upflow installation, including permanent and disposable types.

Product Design - Dual Saver Configuration

Dual Saver Configuration & Operation

Explanation of heating modes (Single Stage, Modified Two-Stage) and dipswitch settings.

Furnace Specifications

Blower Performance Specifications

Blower Performance Data

Tables showing blower performance (CFM & Temperature Rise vs. External Static Pressure) for various models.

Blower Performance Chart

Graphical representation of BTU Output vs. Temperature Rise for blower performance calculations.

Wiring Diagrams

Wiring Diagram Overview

Diagram illustrating electrical connections for the GMH8 furnace, including warnings.

Schematics

Typical Schematic

Schematic of the GMH8 furnace with integrated ignition control, showing component connections.