model number auc1b080a9421ag furnace manual

The AUC1B080A9421AG is an 80,000 BTU high-efficiency gas furnace with AFUE rating up to 96%, single-stage operation, multi-speed ECM blower motor, durable heat exchanger, electronic ignition system, and compatibility with standard thermostat controls. Suitable for residential forced-air heating systems. Below are key sections for safety, features, installation, operation, maintenance, and troubleshooting.

Features at a Glance

Key components: High-efficiency heat exchanger, ECM blower motor, electronic ignition, gas valve, pressure switches, flame sensor, limit switches.

Installation Requirements

Unpack and inspect all components. Ensure proper clearances and ventilation.

1. Location: Install in dry, clean area with adequate combustion air and service access.
2. Venting: Use approved PVC piping for intake and exhaust vents.
3. Gas Connection: Use black iron pipe with proper thread sealant.
4. Electrical: Connect to dedicated 120V circuit with proper grounding.
5. Ductwork: Connect to existing duct system with proper sealing.

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

First-Time Setup

Complete installation verification before initial startup.

1. Gas pressure check: Verify manifold pressure set to 3.5" WC for natural gas.
2. Vent inspection: Ensure all vent connections are secure and properly sloped.
3. Electrical verification: Check all wiring connections and polarity.
4. Thermostat setup: Connect standard 24V thermostat to R, W, G, C terminals.
5. Initial startup: Follow lighting instructions on furnace label.

CAUTION! Only qualified HVAC technicians should perform installation and startup procedures.

Specifications

• Heating Capacity: 80,000 BTU/h input
• AFUE Rating: Up to 96% efficiency
• Gas Type: Natural gas (convertible to LP with kit)
• Blower Motor: ECM variable speed
• Electrical: 120V AC, 60Hz, 8.0 amps
• Venting: PVC (2" minimum diameter)
• Dimensions: 21" W x 21" D x 45" H
• Weight: 125 lbs
• Operating Temp Range: -30°F to 120°F

Controls and Settings

Integrated control board with LED status indicator. Access panel safety switch.

Control Board: LED flash codes for diagnostics, dip switches for blower settings.

Thermostat Connections: R (24V), W (Heat), G (Fan), C (Common), Y (Cool - if equipped). Blower Settings: Adjustable heating and cooling speeds via dip switches. Limit Controls: Automatic high-temperature cut-off. Pressure Switches: Verify proper venting operation. Gas Valve: Single-stage operation with manual shut-off.

Connecting to Ductwork

Proper duct connection ensures efficient airflow and system performance.

1. Turn off power and gas supply before making connections.
2. Seal all duct connections with approved duct sealant.
3. Ensure proper return air sizing (minimum 16" x 20" filter rack).
4. Install condensate drain line with proper trap and slope.
5. Verify airflow with manometer or magnehelic gauge.

Tip: Duct system should be sized to deliver 400 CFM per 10,000 BTU capacity.

Operating Procedures

Normal operation controlled by thermostat. System includes safety interlocks.

1. Startup: Thermostat calls for heat, inducer motor starts, pressure switch closes.
2. Ignition: Hot surface igniter glows, gas valve opens, burner ignition occurs.
3. Operation: Flame sensor verifies ignition, blower starts after heat exchanger warm-up.
4. Shutdown: Thermostat satisfied, gas valve closes, blower continues for cool-down.
5. Safety: All safety devices must be reset manually if tripped.

WARNING! Never operate furnace with access panels removed. Carbon monoxide hazard exists.

Maintenance Schedule

Regular maintenance ensures efficiency and longevity.

• Monthly: Check air filter, replace if dirty
• Annual: Professional inspection and cleaning
• Seasonal: Check vent terminations for obstructions
• Every 5 years: Heat exchanger inspection

Care & Cleaning

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

CAUTION! Do not use water or liquid cleaners on electrical components. Keep combustion area clean and free of debris.

Regulatory Information

ANSI Z21.47/CSA 2.3: Certified for natural gas operation. UL listed. Meets DOE energy efficiency standards. Installation must comply with National Fuel Gas Code NFPA 54 and local building codes. For technical support, contact manufacturer at 1-800-XXX-XXXX or visit www.furnacemanufacturer.com.

Troubleshooting

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

Service: 1-800-XXX-XXXX; www.furnacemanufacturer.com