Ideal Logic System IE fault L0C

What it means

If Restart occurs 5 times within 15 minutes following an L02 lockout, the boiler displays L0C, indicating a persistent ignition failure requiring further investigation.

Likely causes

1. Repeated ignition failures
2. Restart attempted 5 times within 15 minutes
3. Repeated failure to establish ignition after multiple restart attempts within a short time period
4. Flue components not correctly assembled, fixed or supported
5. Flue or flue terminal obstruction
6. Displaced seals on flue extensions
7. Combustion products and inlet air mixing due to flue leakage
8. Incorrect gas type or gas supply pressure/rate not verified prior to commissioning
9. Incorrect gas rate/pressure
10. Poor combustion
11. Air/gas ratio valve fault
12. Flue restriction or leakage
13. CO/CO2 ratio greater than 0.004 indicating combustion deposits or fouling
14. Debris or deposits in heat engine/sump outlet
15. Damaged electrode affecting combustion
16. Condensate trap blockage or drying out
17. Combustion deposits building up on heat exchanger
18. Debris in sump outlet or condensate trap
19. Damaged or worn electrode affecting spark gap
20. Water or gas joint leakage

Where to start

1. Count number of restarts within 15 minute window
2. Investigate underlying cause of repeated ignition failure rather than continuing to restart
3. Ensure external controls are calling for heat and confirm display shows correct status