Goodman Furnace GMP050-3 Manual

The Goodman GMP050-3 is a 50,000 BTU gas furnace with single-stage operation, natural gas compatibility, multi-speed blower, electronic ignition, aluminized steel heat exchanger, and up to 80% AFUE efficiency. Designed for residential heating applications with standard venting requirements. Below are key sections for safety, features, installation, operation, maintenance, and troubleshooting.

1. Features at a Glance 2. Installation Requirements 3. First-Time Setup 4. Specifications 5. Controls and Settings 6. Venting Requirements 7. Operation Instructions 8. Maintenance Procedures 9. Care & Cleaning 10. Regulatory Information 11. Troubleshooting

Features at a Glance

Key components: Aluminized steel heat exchanger, multi-speed blower motor, electronic ignition system, gas valve, limit controls, pressure switch.

FeatureDescription
Heat ExchangerAluminized steel construction for durability
Blower MotorMulti-speed PSC motor for airflow control
Ignition SystemHot surface electronic ignition
Gas ValveSingle-stage automatic gas valve
AFUE RatingUp to 80% Annual Fuel Utilization Efficiency
VentingStandard Category I venting required
Thermostat ConnectionStandard 24V connections
Filter SizeStandard 16x25x1 inch filter
Safety ControlsLimit switches, pressure switch, rollout protection
Power Requirements120V AC, 60Hz

Installation Requirements

Unpack and inspect unit for shipping damage. Verify proper location and clearances.

  1. Location: Install in approved locations with proper clearances to combustibles.
  2. Venting: Install proper Category I venting system according to local codes.
  3. Gas Supply: Connect to natural gas supply with approved piping and shutoff valve.
  4. Electrical: Connect to 120V AC power supply with proper grounding.
  5. Ductwork: Connect to properly sized and sealed duct system.

WARNING! Installation must be performed by qualified HVAC technician. Improper installation can cause fire, explosion, or carbon monoxide poisoning.

First-Time Setup

Initial startup must be performed by qualified technician.

  1. Verify installation: Check all connections, clearances, and venting.
  2. Gas pressure: Set manifold pressure to 3.5" WC for natural gas.
  3. Electrical: Verify proper voltage and polarity.
  4. Startup sequence: Follow manufacturer's startup procedure.
  5. Performance check: Verify proper ignition, heating, and safety operation.

CAUTION! Never attempt to adjust gas pressure or perform startup without proper training and equipment.

Specifications

Controls and Settings

Integrated control board manages all furnace operations. Access via control panel cover.

Control Board: Manages ignition sequence, blower operation, safety controls.

Thermostat Connections: Standard 24V connections (R, W, G, Y, C). Blower Speeds: Multiple speed taps for heating operation. Limit Controls: High temperature safety shutoff. Pressure Switch: Verifies proper venting operation. Ignition Control: Manages hot surface igniter and flame sensing.

Venting Requirements

Category I venting required. Follow local codes and manufacturer specifications.

  1. Vent Type: Use approved Category I vent materials.
  2. Vent Size: Minimum 4" diameter for single furnace.
  3. Clearances: Maintain proper clearances to combustibles.
  4. Termination: Proper outdoor termination location required.
  5. Slope: Horizontal vents must slope upward toward termination.

Tip: Always verify proper draft and venting operation during startup.

Operation Instructions

Normal operation controlled by thermostat.

  1. Thermostat Call: Set thermostat above room temperature for heat call.
  2. Inducer Operation: Inducer motor starts to establish draft.
  3. Ignition Sequence: Hot surface igniter heats up, gas valve opens.
  4. Flame Establishment: Control board verifies flame with flame sensor.
  5. Blower Operation: Blower starts after heat exchanger warms up.
  6. Cycle Completion: Blower continues after gas valve closes to dissipate residual heat.

WARNING! If furnace fails to operate properly, shut off power and gas, then contact qualified service technician.

Maintenance Procedures

Regular maintenance required for safe and efficient operation.

  1. Monthly: Check and replace air filter as needed.
  2. Annual: Professional inspection and cleaning recommended.
  3. Blower: Clean blower assembly and check motor operation.
  4. Heat Exchanger: Inspect for cracks or damage.
  5. Venting: Check vent system for obstructions or damage.
  6. Burners: Clean and inspect burner assembly.

Care & Cleaning

Turn off power before any cleaning. Use soft brush and vacuum for cleaning.

CAUTION! Never use water or liquid cleaners on electrical components. Keep combustion area clean and free of debris.

Regulatory Information

ANSI Z21.47: Certified for natural gas operation. UL Listed. CSA Certified. Manufactured to meet applicable safety standards. For technical support, contact Goodman Manufacturing at 1-877-GOODMAN or visit www.goodmanmfg.com.

Troubleshooting

SymptomPossible CauseCorrective Action
Furnace won't startPower, thermostat, switchCheck power supply; verify thermostat setting; check door switch.
No heatGas supply, ignitionVerify gas valve on; check for ignition attempts; inspect flame sensor.
Short cyclingFilter, limit switchReplace dirty filter; check for restricted airflow; verify limit operation.
Blower won't runMotor, capacitor, controlCheck blower motor; test capacitor; verify control board output.
Unusual noisesMotor, blower, ductsInspect blower wheel; check motor bearings; verify duct connections.

Reset: Turn power off for 30 seconds, then restore power.

Service: 1-877-GOODMAN; www.goodmanmfg.com

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