Service manual

UHD STANDARD DUCT FURNACE INSTALLATION OPERATION AND SERVICE MANUAL
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Figure 18: LED Diagnostic Codes
LED INDICATION FAULT MODE
Slow Flash Normal Operation - No call for heat.
Fast Flash Normal Operation - Call for heat.
2 Flashes Ignition Lockout - No flame detected.
3 Flashes Airflow Fault - Pressure switch open or closed.
4 Flashes Temperature Limit Switch Open
5 Flashes Flame Sense Error - Gas valve not energized.
Steady On Internal Control Failure