The Fraser Johnston PBNU-LD12100D is a high-efficiency gas furnace designed for residential heating applications. This unit features advanced combustion technology, variable-speed blower motor, electronic ignition system, and comprehensive safety controls. Below are key sections covering installation, operation, maintenance, troubleshooting, and technical specifications.
Key components: Gas valve assembly, heat exchanger, blower motor, control board, igniter, flame sensor, pressure switches, and venting system.
| Component | Description |
|---|---|
| Gas Valve | Modulating gas valve for precise fuel control |
| Heat Exchanger | Stainless steel primary and secondary heat exchangers |
| Blower Motor | Variable-speed ECM motor for efficient airflow |
| Control Board | Microprocessor-based control with diagnostic LEDs |
| Ignition System | Hot surface igniter for reliable startup |
| Flame Sensor | Rod-type sensor for flame detection |
| Pressure Switches | Draft and vent pressure safety switches |
| Venting | PVC venting system for sidewall or roof termination |
| Air Filter | Standard 1-inch or 4-inch media filter compatible |
| Thermostat Connection | Compatible with conventional and smart thermostats |
Professional installation required. Follow all local codes and manufacturer specifications.
WARNING! Gas appliances can be hazardous; installation must be performed by qualified technician only.
Power on furnace; thermostat controls operation.
CAUTION! Do not attempt to service while unit is operating. Keep combustible materials away from furnace.
Access control board via front panel door. LED status lights indicate system operation.
Status Lights: Power (green), Heat (yellow), Error (red), Service (amber).
DIP Switch Settings: Blower speeds (high/medium/low), heating stages, accessory configurations. Service Mode: Hold service button for 5 seconds to enter diagnostic mode. Reset Procedure: Power cycle to clear non-lockout errors. Configuration: Jumper settings for thermostat type, fan control, and system options.
Regular maintenance ensures optimal performance and longevity.
Tip: Keep maintenance records for warranty compliance and service history.
Multiple safety systems protect against hazardous conditions.
| Safety Feature | Function |
|---|---|
| Flame Rollout Switch | Detects improper burner flames |
| High Limit Switch | Prevents overheating |
| Pressure Switches | Verify proper venting operation |
| Flame Sensor | Confirms burner ignition |
| Gas Valve | Automatic shutoff if flame not detected |
| Ignition Control | Limited trial for ignition attempts |
WARNING! Never bypass safety devices. Contact qualified technician for safety system issues.
LED flash codes indicate specific system conditions.
| Flash Pattern | Description | Action |
|---|---|---|
| 1 Flash | Pressure Switch Error | Check venting, switch operation |
| 2 Flashes | Ignition Failure | Check gas, igniter, flame sensor |
| 3 Flashes | Limit Switch Lockout | Check airflow, filter, ductwork |
| 4 Flashes | Flame Rollout | Inspect burners, heat exchanger |
| 5 Flashes | Gas Valve Error | Check wiring, valve operation |
| Continuous | Normal Operation | No action required |
Limited warranty coverage for original residential owner.
Note: Warranty void if unit installed by unqualified personnel or used for commercial applications.
UL certified; meets ANSI Z21.47 standards. CSA design certified. Complies with U.S. Department of Energy efficiency standards. Manufactured to meet or exceed industry safety and performance requirements. For technical support, contact Fraser Johnston at 1-800-555-HEAT or visit www.fraserjohnston.com.
| Symptom | Possible Cause | Corrective Action |
|---|---|---|
| Furnace won't start | Power, thermostat, safety lockout | Check circuit breaker, thermostat settings, reset if needed |
| No heat | Gas supply, ignition failure | Verify gas valve open, check error codes, call technician |
| Short cycling | Dirty filter, airflow issues | Replace filter, check vents and registers |
| Blower not running | Motor, capacitor, control board | Check power to blower, inspect motor and capacitor |
| Unusual noises | Mechanical issues, airflow | Inspect blower wheel, motor bearings, ductwork |
| Pilot/ignition problems | Sensor, gas valve, wiring | Clean flame sensor, check gas pressure and ignition |
Reset Procedure: Turn power off for 30 seconds, then restore.
Service: 1-800-555-HEAT; www.fraserjohnston.com