Armstrong Gas Furnace Manual

The Armstrong Gas Furnace is a high-efficiency heating system designed for residential use, featuring advanced combustion technology, multiple safety systems, variable-speed blower motor, electronic ignition, and compatibility with standard thermostat controls. Available in various BTU capacities with AFUE ratings up to 98%. Below are key sections for safety, features, installation, operation, maintenance, and troubleshooting.

Features at a Glance

Key components: Heat exchanger, burners, blower assembly, gas valve, pressure switches, flame sensor, control board, and venting system.

Installation Requirements

Professional installation recommended. Ensure proper clearances and ventilation.

1. Location: Install in well-ventilated area with proper clearances to combustibles.
2. Gas Connection: Use black iron pipe with proper thread sealant; pressure test required.
3. Electrical: 120V AC power supply with proper grounding; dedicated circuit recommended.
4. Venting: PVC pipe system with proper slope and termination clearances.
5. Ductwork: Properly sized and sealed duct system for optimal performance.

WARNING! Gas furnaces produce carbon monoxide; proper venting is critical. Installation must comply with local codes.

First-Time Setup

Initial startup must be performed by qualified technician.

1. Gas pressure adjustment: Set manifold pressure per specifications on rating plate.
2. Venting verification: Confirm proper draft and vent pipe installation.
3. Electrical connections: Verify proper voltage and polarity.
4. Blower speed settings: Adjust for proper airflow and temperature rise.
5. Safety check: Test all safety controls and limit switches.

CAUTION! Never bypass safety controls. Carbon monoxide poisoning can occur if improperly installed.

Technical Specifications

• Input BTU/H: 40,000 - 120,000 (varies by model)
• AFUE Rating: Up to 98% efficiency
• Gas Type: Natural gas or LP (conversion kit required)
• Electrical: 120V AC, 60Hz, 5-15 amp circuit
• Blower Motor: Variable-speed ECM motor
• Venting: 2" or 3" PVC pipe
• Operating Temp Range: -30°F to 120°F ambient
• Sound Rating: Ultra-quiet operation
• Warranty: Limited lifetime heat exchanger, 10 years parts

Controls and Settings

Integrated control board with diagnostic capabilities. Access via control panel or thermostat.

Control Board: POWER switch, Diagnostic LED, DIP switches for configuration.

Thermostat Settings: HEAT/COOL/OFF mode, Fan AUTO/ON, Temperature setpoint. Blower Settings: Adjustable speeds for heating and continuous fan operation. Gas Valve: Pressure adjustment screws (qualified technicians only). Limit Controls: Automatic high-temperature cutoff. Pressure Switches: Verify proper venting operation.

Venting and Gas Connections

PVC vent system for direct vent operation. Gas connection requires proper pipe sizing.

1. Vent Pipe: Use Schedule 40 PVC; maintain 1/4" per foot slope toward furnace.
2. Termination: Keep 12" minimum from windows, doors, and air intakes.
3. Gas Pipe: Size according to length and BTU input; include sediment trap.
4. Pressure Test: 14" W.C. for 15 minutes with no pressure drop.
5. Leak Check: Use soap solution on all connections.

Tip: Always verify venting with manometer during startup.

Operating Instructions

Normal operation via thermostat control.

1. Power On: Ensure furnace switch and circuit breaker are ON.
2. Thermostat Setting: Set to HEAT mode and desired temperature.
3. Startup Sequence: Inducer motor starts, pressure switch proves, igniter heats, gas valve opens, burner ignition.
4. Blower Operation: Blower starts after heat exchanger warm-up delay.
5. Shutdown: Thermostat satisfied, gas valve closes, blower runs for post-purge.
6. Continuous Fan: Set thermostat fan to ON for continuous airflow.

WARNING! If you smell gas, turn off gas supply immediately and call professional.

Maintenance Procedures

Regular maintenance ensures efficiency and safety.

1. Monthly: Check and replace air filter as needed.
2. Annual: Professional inspection and cleaning recommended.
3. Burner Cleaning: Remove and clean burners annually.
4. Heat Exchanger: Visual inspection for cracks or damage.
5. Blower Assembly: Clean blower wheel and housing.
6. Vent System: Inspect for obstructions or damage.
7. Drain System: Clear condensate drain lines and trap.

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

Safety Features

Multiple safety systems protect against hazardous conditions.

Regulatory Information

ANSI Z21.47: Certified for gas-fired central furnaces. CSA International: Approved for US and Canada. UL Certification: Electrical components listed. Energy Star: Qualified for high efficiency ratings. For support, contact Armstrong Air Technical Service at 1-877-874-7378 or visit www.armstrongair.com.

Troubleshooting

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

Service: 1-877-874-7378; www.armstrongair.com