Goodman Furnace GDMP050-3 Manual

The Goodman GDMP050-3 is a 50,000 BTU multi-position gas furnace with AFUE rating, direct vent system, electronic ignition, multi-speed blower motor, and built-in safety controls. Designed for residential heating applications with compatibility for horizontal, upflow, or downflow installation configurations. Below are key sections for safety, features, installation, operation, maintenance, and troubleshooting.

Features at a Glance

Key components: Gas valve, heat exchanger, blower assembly, control board, pressure switches, flame sensor, igniter.

Installation Requirements

Proper installation is critical for safe and efficient operation.

1. Location selection: Choose area with adequate clearance and combustion air.
2. Venting: Install PVC vent pipes according to local codes and manufacturer specifications.
3. Gas connection: Use approved gas piping materials; pressure test for leaks.
4. Electrical: Connect to 120V AC power with proper grounding.
5. Ductwork: Ensure proper sizing and sealing of supply and return ducts.

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

First-Time Setup

Initial startup and configuration procedures.

1. Verify installation: Check all connections, clearances, and venting.
2. Gas pressure adjustment: Set manifold pressure to specifications on rating plate.
3. Blower speed setting: Adjust for proper airflow based on installation.
4. Thermostat connection: Connect compatible 24V thermostat.
5. Test operation: Start furnace and verify proper ignition sequence.

CAUTION! Never bypass safety controls. Always follow startup procedure exactly.

Specifications

• Heating Capacity: 50,000 BTU/H input
• AFUE Rating: High efficiency percentage
• Gas Type: Natural gas (convertible to LP with kit)
• Electrical: 120V AC, 60Hz
• Blower Motor: Multi-speed PSC motor
• Venting: 2-inch PVC pipe required
• Dimensions: Standard furnace cabinet size
• Weight: Approximate shipping weight
• Sound Rating: Quiet operation design
• Warranty: Limited lifetime heat exchanger warranty

Controls and Settings

Integrated control board manages all furnace operations.

Control Board: LED status lights, dip switch settings, diagnostic codes.

Blower Speed: Adjustable for heating and continuous fan operation. Gas Valve: Regulates gas flow with pressure test ports. Limit Switches: High temperature safety cutoffs. Pressure Switches: Verify proper venting operation. Flame Sensor: Detects burner flame presence. Igniter: Hot surface ignition device.

Venting System

Direct vent design for safety and efficiency.

1. Vent pipe installation: Use approved PVC materials only.
2. Termination clearances: Maintain required distances from windows and openings.
3. Slope requirements: Proper pitch for condensation drainage.
4. Combustion air: Ensure adequate fresh air supply.

Tip: Always check local building codes for venting requirements.

Operation Instructions

Normal furnace operation sequence.

1. Thermostat call: Thermostat signals for heat.
2. Inducer operation: Combustion blower starts and proves airflow.
3. Ignition sequence: Hot surface igniter glows, gas valve opens.
4. Flame establishment: Flame sensor confirms ignition.
5. Main blower: Blower starts after heat exchanger warm-up delay.
6. Cycle completion: Furnace runs until thermostat satisfied.

WARNING! Never operate furnace with access panels removed.

Maintenance Procedures

Regular maintenance ensures optimal performance and safety.

1. Filter replacement: Change 1-inch filter monthly during heating season.
2. Cleaning: Vacuum burners and heat exchanger annually.
3. Inspection: Check flame sensor and igniter for wear.
4. Venting: Inspect vent pipes for obstructions or damage.
5. Professional service: Annual inspection by qualified technician.

CAUTION! Turn off power and gas supply before performing maintenance.

Safety Information

Carbon monoxide detectors required in living spaces. Never store flammable materials near furnace. Keep combustion air openings clear.

EMERGENCY SHUTOFF: Know location of gas shutoff valve and electrical disconnect.

Regulatory Information

UL listed and ANSI certified. Complies with applicable safety standards. Manufactured to meet DOE efficiency requirements. For technical support, contact Goodman Manufacturing at 1-877-GOODMAN or visit www.goodmanmfg.com.

Troubleshooting

Reset: Power cycle furnace to clear temporary faults.

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