American Standard HVAC YCX042G3-M Manual

The American Standard YCX042G3-M is a high-efficiency, single-stage, 3.5-ton residential gas furnace designed for reliable heating performance. It features a durable aluminized steel heat exchanger, electronic ignition, variable-speed blower motor, integrated diagnostic controls, and compatibility with various thermostat systems. Below are key sections for safety, features, installation, setup, operation, maintenance, and troubleshooting.

Features at a Glance

Key components: Aluminized steel tubular heat exchanger, variable-speed ECM blower motor, electronic hot surface ignition, integrated control board with diagnostic LED, multi-speed taps, and flue outlet.

Installation

Unpack and inspect contents. Ensure proper location with adequate clearance.

1. Position furnace: Place on level surface in approved location (closet, attic, basement).
2. Connect venting: Attach PVC pipe to flue outlet per local codes.
3. Connect gas supply: Use approved black iron pipe; leak test required.
4. Connect electrical: 115V power supply; connect thermostat wiring (R, W, G, C, Y).
5. Connect ductwork: Attach supply and return ducts securely.
6. Install filter: Insert 1-inch or 4-inch filter into filter rack.

WARNING! Installation must be performed by a qualified HVAC technician in accordance with all local codes and manufacturer instructions. Gas leaks can cause explosion or fire.

First-Time Setup

After installation, perform initial startup and configuration.

1. Power on: Turn on electrical power to furnace.
2. Set thermostat: Install compatible thermostat and set to HEAT mode.
3. Check gas pressure: Manifold pressure should be set to 3.5" W.C. for natural gas.
4. Test operation: Initiate heating cycle via thermostat; observe ignition sequence.
5. Adjust blower speed: Select appropriate heating speed tap on control board if needed.
6. Verify safety controls: Ensure all switches (rollout, limit) are functioning.

CAUTION! Do not bypass safety devices. Ensure proper ventilation to prevent carbon monoxide buildup.

Specifications

• Model: YCX042G3-M
• Heating Capacity: 42,000 BTU/hr Input, 33,600 BTU/hr Output
• Efficiency (AFUE): 80%
• Stages: Single-Stage Heating
• Motor Type: Variable-Speed ECM Blower
• Electrical: 115V AC, 60Hz, 7.0 amps (max)
• Gas Type: Natural Gas (convertible to LP with kit)
• Gas Pressure: 3.5" W.C. Natural Gas, 10" W.C. LP
• Vent Size: 3-inch PVC
• Dimensions (HxWxD): 40" x 17.5" x 21"
• Weight: 98 lbs

Controls and Settings

Access control board via front panel. Diagnostic LED indicates status codes.

Control Board: POWER switch, Fuse (3-amp), Diagnostic LED, DIP switches for configuration, terminal strip (R, W, G, C, Y).

DIP Switch Settings: SW1-1: Continuous fan delay; SW1-2: Ignition retry; SW1-3: Blower off delay. Diagnostic Codes: 1 flash = Normal operation; 2 flashes = Pressure switch fault; 3 flashes = Ignition lockout; 4 flashes = Limit circuit fault; 5 flashes = Flame rollout fault. Blower Speed Taps: HEAT (black wires): Tap 1 (low) to Tap 5 (high); COOL (blue wires): Tap 1 (low) to Tap 5 (high).

Connecting Thermostat

Compatible with most 24V thermostats (single-stage heat, single-stage cool).

1. Turn off power to furnace at disconnect or breaker.
2. Remove control board access panel.
3. Connect thermostat wires to terminal strip: R (24V power), W (Heat), G (Fan), Y (Cool), C (Common).
4. Secure wires; replace panel.
5. Restore power; configure thermostat for single-stage gas furnace.

Tip: Use 18-gauge thermostat wire. Ensure C wire is connected for proper operation of smart thermostats.

Operation

Normal heating cycle sequence.

1. Thermostat calls for heat: Sends signal to control board.
2. Inducer motor starts: Creates draft through heat exchanger.
3. Pressure switch closes: Verifies draft.
4. Hot surface igniter glows: Heats up for ignition.
5. Gas valve opens: Gas flows to burners.
6. Ignition: Burners light; flame sensor confirms.
7. Blower starts: After heat exchanger warms up (blower-on delay).
8. Cycle ends: When thermostat satisfied, gas valve closes, blower runs post-purge.

WARNING! If you smell gas, turn off gas supply immediately, evacuate, and call gas company. Do not operate furnace until leak is repaired.

Maintenance

Regular maintenance ensures efficiency and longevity. Perform annually by qualified technician.

1. Inspect heat exchanger: Check for cracks or corrosion.
2. Clean burners: Remove debris; ensure proper flame pattern.
3. Check gas pressure: Adjust if necessary.
4. Inspect vent system: Ensure no obstructions or damage.
5. Lubricate motor (if required): Some models have sealed bearings.
6. Test safety controls: Verify operation of limit and rollout switches.
7. Check filter: Replace or clean monthly during heating season.

Care & Cleaning

Turn off power before servicing. Keep area around furnace clear.

Filter: Replace 1-inch filter monthly; 4-inch media filter every 6-12 months.

Exterior: Wipe with dry cloth; do not use water or cleaners.

Vents: Ensure intake and exhaust vents are clear of snow, leaves, or debris.

CAUTION! Do not attempt to clean internal components unless qualified. Compressed air can be used carefully on blower wheel and burners by technician.

Regulatory Information

UL listed; ANSI Z21.47/CSA 2.3 compliant. Manufactured to comply with U.S. Department of Energy efficiency standards. This product contains materials that may be recyclable. Check local regulations for disposal. For technical support, contact American Standard at 1-800-926-9667 or visit www.americanstandardair.com. Copyright © American Standard Heating & Air Conditioning.

Troubleshooting

Reset: Turn power off for 30 seconds to reset control board. If problem persists, call technician.

Service: 1-800-926-9667; www.americanstandardair.com