Furnace error code lookup

Type the code or flash count. Every result shows what it means, what to check and a guide to fix it.

Codes depend on the control board, so each chart names the furnace series it came from. Always confirm against the label inside the furnace door.

Charts by brand

Fix guides

• Ignition lockout / failed ignition
• Flame sense problems
• Pressure switch open or stuck closed
• High limit tripping
• Rollout switch tripped
• Blown 3 A control fuse