Trane Package Unit: YSC
Re: Ignition Lockout Codes
Trane YSC package units are multi-stage gas/electric units.
| Light Status | Description |
| Off | Check Control Power |
| Continuous On | Normal, No Heat Call |
| Slow Flash | Normal, Call for Heat |
| Fast Flash | Internal Control Failure |
| 1 | Communication Failure |
| 2 | Ignition Lockout |
| 3 | Pressure Switch Problem |
| 4 | High Limit (TCO1 or TCO2) Open |
| 5 | Flame Sensed with Gas Valve Off |
| 6 | Flame Rollout Switch (FL) Open |