Manual for American Standard Furnace Model AUH2C100A9V4VAA

The American Standard Furnace Model AUH2C100A9V4VAA is a high-efficiency gas furnace with 100,000 BTU input capacity, variable-speed blower motor, two-stage heating operation, and compatibility with various thermostat systems. 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. Operation Procedures 8. Safety Features 9. Maintenance & Cleaning 10. Regulatory Information 11. Troubleshooting

Features at a Glance

Key components: Two-stage gas valve, variable-speed ECM blower motor, hot surface igniter, flame sensor, pressure switches, and integrated control board.

Feature	Description
Gas Valve	Two-stage operation for efficient heating
Blower Motor	Variable-speed ECM for quiet operation
Ignition System	Hot surface igniter for reliable startup
Flame Sensor	Safety feature to detect flame presence
Pressure Switches	Ensure proper venting operation
Control Board	Integrated system management
Filter Rack	Standard 1-inch filter compatibility
Drain Connection	For condensate removal
Gas Connection	1/2-inch NPT gas line connection
Electrical Connection	120V AC power supply

Installation

Unpack and inspect contents. Position in approved location with proper clearances.

Gas line connection: Use approved pipe compound; pressure test for leaks.
Vent piping: Install PVC vent pipes according to local codes and manufacturer specifications.
Electrical wiring: Connect 120V AC power supply; install disconnect switch within sight.
Thermostat wiring: Connect compatible two-stage thermostat with proper wiring.
Drain line: Install condensate drain line with proper slope and trap.

WARNING! Gas furnace installation must be performed by qualified technician only. Ensure proper ventilation and combustion air supply.

First-Time Setup

Power on furnace; follow startup sequence.

System check: Verify all connections are secure and proper.
Gas pressure adjustment: Set manifold pressure to specifications (3.5" WC natural gas).
Blower speed settings: Adjust dip switches for proper airflow.
Thermostat configuration: Program for two-stage operation.
Test operation: Run through complete heating cycle to verify proper function.

CAUTION! Never bypass safety controls. Ensure proper combustion and ventilation before operation.

Specifications

Heating Capacity: 100,000 BTU Input
Efficiency: Up to 96% AFUE
Stages: Two-stage heating operation
Blower Type: Variable-speed ECM
Gas Type: Natural Gas
Electrical: 120V AC, 60Hz
Manifold Pressure: 3.5" WC Natural Gas
Vent Size: 2-inch PVC
Filter Size: 16x25x1 inches
Operating Temp Range: -30°F to 150°F ambient

Controls and Settings

Access control board via front panel removal. Integrated control board with status LED for diagnostics.

Thermostat: Compatible with two-stage heating thermostats; requires W1/W2 connections.

Blower Settings: Adjustable via dip switches for airflow customization. Gas Valve: Two-stage operation with pressure regulation. Safety Controls: Flame rollout switches, pressure switches, high limit switch. Diagnostic LED: Flashing codes indicate system status and error conditions.

Connecting Components

Gas Line: 1/2-inch NPT connection. Vent System: PVC piping. Electrical: 120V AC power. Thermostat: Standard 24V connections.

Turn off gas and electrical power before making connections.
Use approved materials for all gas and vent connections.
Follow local codes for clearances and installation requirements.
Test all connections for leaks before operation.

Tip: Always use two wrenches when making gas connections to prevent damage to gas valve.

Operation Procedures

Normal heating cycle operation with two-stage capability.

Startup: Thermostat calls for heat; control board initiates ignition sequence.
Ignition: Hot surface igniter heats up; gas valve opens first stage.
Flame detection: Flame sensor confirms ignition; system enters heating mode.
Second stage: If needed, control board activates second stage for higher heat output.
Blower operation: Variable-speed blower adjusts airflow for optimal comfort.
Shutdown: Thermostat satisfied; gas valve closes; blower continues for post-purge.

WARNING! Never operate furnace without proper venting and combustion air. Monitor for unusual noises or odors.

Safety Features

Flame Rollout Switches: Detect improper burner operation. Pressure Switches: Ensure proper venting. High Limit Switch: Prevents overheating. Flame Sensor: Confirms proper ignition. Ignition Lockout: Prevents repeated ignition attempts.

Maintenance & Cleaning

Turn off power and gas supply before maintenance. Replace air filter monthly during heating season. Clean burners and heat exchanger annually. Inspect vent system for obstructions.

CAUTION! Only qualified technicians should perform internal maintenance. Never operate with blocked vents or dirty filters.

Regulatory Information

ANSI Z21.47: Certified for natural gas operation. UL Listed: Meets safety standards. For support, contact American Standard at 1-800-572-1111 or visit www.americanstandardair.com. Installation must comply with local building codes and utility requirements.

Troubleshooting

Symptom	Possible Cause	Corrective Action
No heat	Power, thermostat, gas supply	Check circuit breaker; verify thermostat setting; ensure gas valve open.
Furnace locks out	Ignition failure	Check for blocked vent; verify gas pressure; inspect flame sensor.
Blower not running	Motor, control board	Check for proper voltage; inspect control board connections.
Short cycling	Dirty filter, high limit	Replace air filter; check for restricted airflow; verify limit switch operation.
Unusual noises	Blower, burners	Inspect blower wheel; clean burners; check for loose components.

Reset: Power cycle furnace to reset control board lockout.

Service: 1-800-572-1111; www.americanstandardair.com