Ideal Fault Codes
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Ideal Fault Codes
Boilers covered:
- Ideal Logic Combi — original generation
- Ideal Logic System — original generation
- Ideal Logic Heat — original generation
- Ideal Independent Combi
- Ideal Independent System
- Ideal Logic Combi ESP1
- Ideal Logic Code Combi ESP1
- Ideal Vogue Gen2 Combi
- Ideal Vogue Gen2 System
- Ideal Vogue MAX Combi
- Ideal Vogue MAX System
- Ideal Logic MAX Combi — original generation
- Ideal Logic MAX System — original generation
- Ideal Logic MAX Heat — original generation
- Ideal Logic+ Combi
- Ideal Logic+ System
- Ideal Logic+ Heat
- Ideal Logic Combi²
- Ideal Logic System²
- Ideal Logic Heat²
- Ideal i-mini²
Note: F1 (low pressure) is frequently user-fixable. L-codes are lockouts. Always check your specific model manual.
Modern / Logic Range
| Error code | Possible fault | If ticked try the troubleshooter |
|---|---|---|
| F / F0 | Frost mode active (not a fault) | ✕ |
| F1 | Low water pressure | ✓ |
| F2 / FN / LN | Flame loss | ✓ |
| F3 | Fan fault | ✕ |
| F4 / L4 | Flow thermistor / control thermistor fault | ✕ |
| F5 / L5 | Return thermistor fault | ✕ |
| F6 | Outside sensor fault | ✕ |
| F7 | Low incoming mains voltage | ✕ |
| F8 / L8 | PCB or configuration fault | ✕ |
| F9 / L9 | Unconfigured PCB or overheat lockout (model dependent) | ✕ |
| F10 | DHW temperature sensor fault | ✕ |
| F11 | Cylinder sensor fault | ✕ |
| FD | No water flow detected / condensate blocked (some models) | ✓ |
| FU | Flow/return differential too high (>50°C) | ✕ |
| FA | Negative difference between flow and return thermistors / sensors reversed | ✕ |
| L0 | Safety limit lockout (generic) | ✕ |
| L1 | Lockout — flow temperature too high or water flow too low | ✕ |
| L2 | Ignition lockout / flame has gone out | ✓ |
| L6 | False flame (flame detected with no demand) | ✕ |
| L10 | Overheat lockout — maximum temperature exceeded | ✕ |
| LC | Too many resets in 15 minutes | ✕ |
| C0 | Boiler chip card activation not completed | ✕ |
| C1 / C2 / C9 | Boiler chip card / EEPROM faults | ✕ |
| LC | Too many resets in 15 minutes | ✕ |
| L5 | 5 boiler resets in 15 minutes / return thermistor | ✕ |
| L6 | False flame lockout | ✕ |
| L8 | PCB or configuration fault | ✕ |
| L9 | PCB unconfigured or fault | ✕ |
| FU | Flow/return differential > 50°C | ✕ |
| FA | Flow/return reversed | ✕ |
| FN | Flame loss | ✓ |
| LN | Flame loss | ✓ |
Older Models (Isar / Icos / HE)
| Error code | Possible fault | If ticked try the troubleshooter |
|---|---|---|
| L-F / LF / FL | Flame detection error / ignition lockout (gas, electrodes, condensate, gas valve) | ✓ |
| L-A / LA | Overheat lockout (low pressure, circulation, thermistor, overheat stat) | ✓ |
| L-E / LE / H-E / HE | PCB internal fault | ✕ |
| L-8 / L8 | Fan error | ✕ |
| H-1 / H1 | Flow thermistor error | ✕ |
| H-3 / H3 | DHW thermistor error | ✕ |
| H-F / HF | Short circuit error (PCB) | ✕ |
| H-4 / H4 | Flue thermistor error | ✕ |
| F1 | Low water pressure | ✓ |
| F2 / FL / L2 / FN / LN | Flame loss / ignition failure | ✓ |
| L2 | Ignition lockout / flame detection problem | ✓ |