Goodman Service Manual GMV95 Furnace IO-280H

The Goodman GMV95 Furnace IO-280H is a high-efficiency gas furnace with variable-speed ECM motor, two-stage heating capability, AFUE rating up to 95%, diagnostic LED system, integrated control board, pressure switch monitoring, flame sensor, hot surface ignitor, gas valve control, condensate drainage system, and multi-speed blower operation. Designed for residential HVAC applications with 120V AC power supply. Below are key sections for safety, features, installation, setup, operation, and troubleshooting.

1. Features at a Glance 2. Installation 3. First-Time Setup 4. Specifications 5. Controls and Settings 6. Connecting Components 7. Operating Procedures 8. Diagnostic Features 9. Maintenance & Cleaning 10. Regulatory Information 11. Troubleshooting

Features at a Glance

Key components: Variable-speed ECM blower motor, two-stage gas valve, hot surface ignitor, flame sensor, pressure switches, condensate trap, diagnostic LED, integrated furnace control board.

Feature	Description
Variable-speed ECM motor	Energy-efficient blower operation with multiple speed settings
Two-stage heating	High/low fire operation for improved comfort and efficiency
Diagnostic LED system	Flashing code indicators for fault diagnosis
Hot surface ignitor	Silicon carbide ignition system
Flame sensor	Microamp flame detection for safety
Pressure switches	Draft inducer and vent safety monitoring
Gas valve	Two-stage gas flow control
Condensate system	Drainage for high-efficiency operation
Control board	Integrated furnace controller with diagnostic capabilities
Blower compartment	Multi-speed airflow adjustment

Installation

Unpack and inspect all components. Ensure proper clearances and venting requirements.

Position furnace: Place on stable, level surface with proper clearances.
Install venting: Connect PVC vent pipes according to local codes.
Connect gas supply: Use approved gas line with shut-off valve.
Electrical connections: Connect 120V power and thermostat wiring.
Drain connections: Install condensate drain line with trap.
Ductwork: Connect supply and return air ducts.

WARNING! Gas furnaces produce carbon monoxide; ensure proper venting. Only qualified technicians should install.

First-Time Setup

Power on furnace; verify proper operation and settings.

Gas pressure adjustment: Set manifold pressure per specifications.
Blower speed settings: Adjust dip switches for proper airflow.
Thermostat configuration: Set up for two-stage operation.
System checkout: Verify ignition sequence and safety controls.
Combustion analysis: Check CO levels and efficiency.

CAUTION! Verify gas connections for leaks before operation. Follow all local codes.

Specifications

Model: GMV95 IO-280H
Input BTU/H: 80,000 (Two-stage)
AFUE Rating: Up to 95%
Motor Type: Variable-speed ECM
Stages: Two-stage heating
Voltage: 120V AC, 60Hz
Gas Type: Natural Gas
Manifold Pressure: 3.5" WC (Natural Gas)
Venting: PVC Category IV
Dimensions: Standard furnace cabinet size

Controls and Settings

Access control board via front panel. Diagnostic LED provides fault codes.

Control Board: Integrated furnace controller with LED status indicators, dip switch settings, terminal connections.

Heating Stages: Two-stage operation with timing controls. Blower Settings: ECM motor with multiple speed configurations via dip switches. Safety Controls: Pressure switches, flame rollout switches, high limit controls. Diagnostic Codes: LED flash patterns for troubleshooting (1 flash, 2 flash, etc.).

Connecting Components

Thermostat: Standard 24V connections. Power: 120V supply. Gas: 1/2" or 3/4" gas line. Venting: 2" or 3" PVC.

Turn off power and gas supply before connecting.
Match thermostat wires to correct terminals (R, W, W2, G, C, Y).
Verify proper gas line sizing and pressure.
Ensure vent pipes are properly sloped and supported.

Tip: Use approved pipe sealant on gas connections. Check all electrical connections for tightness.

Operating Procedures

Normal heating sequence with two-stage operation.

Call for heat: Thermostat initiates heating cycle.
Inducer operation: Draft inducer motor starts and pressure switch proves.
Ignition sequence: Hot surface ignitor heats up.
Gas valve opening: Gas flows to burners.
Flame detection: Flame sensor confirms ignition.
Blower operation: ECM blower starts after heat exchanger warm-up.
Stage operation: Second stage engages if needed for temperature demand.
Shutdown: Gas valve closes, blower continues for post-purge.

WARNING! Never bypass safety controls. Monitor for proper flame and venting.

Diagnostic Features

LED fault codes: Monitor control board LED for flash patterns indicating specific issues. Pressure switch monitoring: Ensures proper venting. Flame sensing: Microamp reading verification. Limit controls: Over-temperature protection.

Maintenance & Cleaning

Turn off power before servicing. Regular maintenance includes filter changes, burner inspection, flame sensor cleaning, and condensate system check.

CAUTION! Gas appliances require qualified technician service. Keep combustion area clean and clear.

Regulatory Information

ANSI Z21.47: Certified for natural gas operation. UL listed. CSA certified. Meets DOE efficiency standards. Copyright © Goodman Manufacturing Company, L.P. For technical support, contact Goodman at 1-877-466-8626 or visit www.goodmanmfg.com.

Troubleshooting

Symptom	Possible Cause	Corrective Action
No heat	Power, thermostat, gas supply	Check power, thermostat setting, gas valve position, circuit breakers.
Furnace locks out	Safety controls, flame detection	Check LED codes, flame sensor, pressure switches, venting.
Blower not running	Motor, capacitor, control board	Verify power to motor, check ECM module, inspect control board.
Ignition failure	Ignitor, gas valve, pressure	Test ignitor continuity, check gas pressure, verify valve operation.
Condensate issues	Drain line, trap, pump	Clear drain lines, check trap installation, verify pump operation.

Reset: Power cycle furnace to reset lockout conditions.

Service: 1-877-466-8626; www.goodmanmfg.com