2+5
MODEL SELECTION OR SETUP ERROR. Either model plug (PL4) is missing or incorrect, or setup switch SW1-1 or SW1-6 is positioned improperly.
This code typically points to
- Missing PL4 model plug
- Wrong PL4 model plug
- SW1-1 left ON after code recall
- SW1-6 left ON after component test
- Simultaneous SW1-1 and SW1-6 ON
- Mismatched twinned furnace models
- Wrong replacement control
Next checks to confirm
- Confirm correct PL4 is installed
- Check whether code flashed only 4 times at power-up or flashes continuously
- Verify SW1-1 is OFF unless intentionally retrieving history
- Verify SW1-6 is OFF unless intentionally running component test
- Check for mismatched twinning
- Confirm replacement board type and software level
Escalation
Escalate to board/parts verification if PL4 is correct, switches are correctly positioned, twinning is valid, and code persists.
Reset behavior
No timed auto-reset. Clear by correcting model-plug/setup condition. In component-test context: turn SW1-6 OFF and then back ON to repeat test.
Urgent
Fix now