Rheem 80 Plus Furnace Manual

The Rheem 80 Plus Furnace is a high-efficiency gas furnace with AFUE ratings of 80% or higher, featuring advanced heat exchanger technology, electronic ignition system, variable-speed blower motor, multi-speed operation, built-in diagnostic controls, safety shut-off features, and compatibility with standard thermostat systems. Designed for residential heating applications with natural gas or propane capability. Below are key sections for safety, features, installation, setup, operation, maintenance, and troubleshooting.

Features at a Glance

Key components: High-efficiency heat exchanger, electronic ignition system, variable-speed blower, diagnostic control board, gas valve, pressure switches, flame sensor, and filter compartment.

Installation Requirements

Professional installation recommended. Verify local codes and obtain permits.

1. Location: Install in dry, well-ventilated area with proper clearances.
2. Venting: Properly size and install vent pipes according to manufacturer specifications.
3. Gas Connection: Use approved gas piping materials; pressure test for leaks.
4. Electrical: Connect to dedicated 120V circuit with proper grounding.
5. Ductwork: Ensure proper sizing and sealing of supply/return ducts.

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

First-Time Setup

After installation, perform initial startup procedure.

1. Verify all connections: Gas, electrical, venting, and ductwork.
2. Install air filter: Ensure proper size and orientation.
3. Set thermostat: Program desired temperature settings.
4. Power on: Switch furnace power on at unit and electrical panel.
5. Test operation: Initiate heating cycle and verify proper operation.
6. Check airflow: Ensure adequate airflow from all registers.

CAUTION! Only qualified HVAC technicians should perform initial startup and testing.

Specifications

• AFUE Rating: 80% or higher efficiency
• Fuel Type: Natural gas or propane (conversion kit required)
• Heating Capacity: 40,000 to 120,000 BTU/hr (model dependent)
• Blower Motor: Variable-speed ECM technology
• Electrical: 120V, 60Hz, dedicated circuit
• Venting: Category I venting required
• Filter Size: Standard 1" or optional 4" media filter
• Warranty: Limited lifetime heat exchanger warranty
• Dimensions: Varies by model (check specific model documentation)

Controls and Settings

Access control board via front panel. Diagnostic LEDs indicate system status.

Control Board: POWER switch, diagnostic LED lights, dip switch settings for blower speeds.

Thermostat Settings: HEAT/COOL/OFF mode, temperature setpoint, fan AUTO/ON. Blower Speeds: Adjustable via dip switches for heating and continuous fan operation. Diagnostic Codes: LED flash patterns indicate specific error conditions. Safety Controls: Limit switches, pressure switches, flame rollout protection.

Connecting Thermostat

Compatible with standard 24V thermostats. Follow wiring diagram for proper connections.

1. Turn off power to furnace at electrical panel.
2. Remove thermostat cover and identify wire connections.
3. Match wires to terminals: R (power), W (heat), G (fan), C (common).
4. Secure connections and replace cover.
5. Restore power and test thermostat operation.

Tip: Use compatible thermostat for optimal performance; programmable models recommended for energy savings.

Operating Procedures

Normal operation controlled by thermostat settings.

1. Set thermostat to HEAT mode and desired temperature.
2. Furnace will initiate startup sequence: inducer motor, pressure switch verification, igniter warm-up, gas valve opening.
3. Burner ignition confirmed by flame sensor.
4. Blower motor activates after heat exchanger warm-up period.
5. System cycles off when thermostat setpoint reached.
6. For continuous fan operation, set thermostat fan to ON position.

WARNING! Never attempt to manually override safety controls. If furnace fails to start, consult troubleshooting section.

Maintenance Schedule

Regular maintenance ensures optimal performance and safety.

Care & Cleaning

Turn off power before any cleaning. Keep area around furnace clear and clean.

1. Air Filter: Replace every 1-3 months depending on usage and environment.
2. Exterior: Wipe with dry cloth; avoid water or cleaning chemicals.
3. Vents: Keep intake and exhaust vents clear of debris and snow.
4. Ductwork: Professional cleaning recommended every 3-5 years.

CAUTION! Do not use compressed air to clean internal components; may damage sensitive electronics.

Regulatory Information

UL listed and ANSI certified. Complies with U.S. Department of Energy efficiency standards. Manufactured to meet or exceed ASHRAE standards. For natural gas operation: ANSI Z21.47; for propane operation: ANSI Z21.47. Copyright © Rheem Manufacturing Company. All rights reserved. For technical support, visit www.rheem.com or contact 1-800-432-8373.

Troubleshooting

Reset: Turn power off for 30 seconds, then restore. If problem persists, call professional service.

Service: 1-800-432-8373; www.rheem.com