The Rheem Criterion II Gas Furnace is a high-efficiency residential heating system featuring advanced combustion technology, electronic ignition, multi-speed blower motor, safety controls, and diagnostic LED indicators. Available in various BTU capacities with AFUE ratings up to 96%. Below are key sections for safety procedures, technical specifications, installation guidelines, maintenance procedures, troubleshooting, and parts identification.
Critical safety warnings and precautions for service technicians and homeowners.
| Hazard | Precaution |
|---|---|
| Gas Leaks | Use leak detection solution; never use open flame |
| Electrical Shock | Disconnect power before servicing |
| Carbon Monoxide | Ensure proper ventilation and flue installation |
| Hot Surfaces | Allow unit to cool before servicing |
| Combustible Materials | Maintain clearances per installation manual |
WARNING! Only qualified technicians should perform service. Always follow local codes and regulations.
Proper installation procedures for optimal performance and safety.
CAUTION! Improper installation may create hazardous conditions and void warranty.
Key components and their functions within the furnace system.
| Component | Function |
|---|---|
| Gas Valve | Controls gas flow to burners |
| Inducer Motor | Creates draft for combustion |
| Heat Exchanger | Transfers heat to air stream |
| Blower Assembly | Circulates air through system |
| Control Board | Manages furnace operation |
| Limit Switches | Safety temperature controls |
| Pressure Switches | Verify proper venting |
| Igniter | Hot surface ignition device |
| Flame Sensor | Detects burner flame |
Step-by-step procedure for initial furnace start-up and commissioning.
Normal operating characteristics and user controls.
Thermostat Operation: Set to desired temperature; system will cycle automatically.
Blower Operation: Multi-speed motor adjusts airflow based on heating requirements.
Ignition Sequence: Inducer motor starts, pressure switch closes, igniter heats, gas valve opens, flame sensor confirms ignition.
Safety Features: Multiple limit switches, pressure switches, and roll-out switches protect against unsafe conditions.
Recommended maintenance schedule and procedures.
Common problems and corrective actions.
| Symptom | Possible Cause | Corrective Action |
|---|---|---|
| No heat | Thermostat, power, gas supply | Check thermostat setting, circuit breaker, gas valve |
| Furnace won't start | Limit switch, pressure switch | Reset limit switch; check pressure switch tubing |
| Short cycling | Dirty filter, airflow restriction | Replace filter; check registers and ductwork |
| Blower won't stop | Fan switch, control board | Check thermostat fan setting; test control board |
| Unusual noises | Motor bearings, ductwork | Lubricate motor; check for loose panels or ducts |
| Pilot/ignition failure | Igniter, flame sensor | Test igniter; clean flame sensor |
LED flash codes and their meanings for diagnostic purposes.
| Flash Code | Description | Action |
|---|---|---|
| 1 Flash | Limit circuit fault | Check airflow, filter, limit switch |
| 2 Flashes | Pressure switch stuck open | Check inducer, venting, switch |
| 3 Flashes | Pressure switch stuck closed | Check switch, wiring, control board |
| 4 Flashes | Ignition failure | Check gas, igniter, flame sensor |
| 5 Flashes | Gas valve circuit fault | Check valve, wiring, control board |
| 6 Flashes | Blower fault | Check motor, capacitor, wiring |
| 7 Flashes | Roll-out switch fault | Check burners, heat exchanger |
Common replacement parts and their identification numbers.
Manufacturer warranty coverage and terms.
Heat Exchanger: 20-year limited warranty
Parts: 5-year limited warranty
Labor: 1-year limited warranty
Registration: Product must be registered within 90 days of installation
Exclusions: Damage from improper installation, misuse, or lack of maintenance
For warranty service, contact Rheem at 1-800-432-8373 or visit www.rheem.com