Complete guide to Logic, Logic+, Vogue, Mexico, Mini series fault codes with troubleshooting advice
Ideal boilers display fault codes on the screen when they detect a problem. These codes help identify what's wrong so it can be fixed quickly.
Tip: Ideal fault codes use letters and numbers (e.g., F1, L1, L2, C2). Note down the exact code shown on your boiler display.
| Code | Meaning | Quick Fix | DIY? |
|---|---|---|---|
| F1 | Low water pressure - system below safe operating level | Top up pressure using filling loop to 1.0-1.5 bar, reset boiler | Yes |
| FD | System circulation fault - inadequate water flow | Check pressure, bleed radiators, ensure pump is working | Partial |
| FE | Water pressure too high | Bleed a radiator to release excess pressure | Partial |
| F0 | Water pressure sensor fault | Reset boiler | No |
| FA | Pressure drop detected | Check for leaks, top up pressure | Partial |
| Code | Meaning | Quick Fix | DIY? |
|---|---|---|---|
| L1 | Gas valve proving fault | Reset boiler, check gas supply is on | No |
| L2 | Ignition failure - boiler failed to light | Check gas supply is on, thaw frozen condensate pipe in winter, reset boiler | Partial |
| L5 | False flame detection - flame sensed when shouldn't be | Do NOT reset repeatedly - call Gas Safe engineer immediately | No |
| L9 | Flame lost during operation | Check gas supply, check for frozen condensate pipe, reset | Partial |
| L3 | Flame lift off - flame unstable | Reset boiler | No |
| L4 | Flame lost at end of sequence | Reset boiler | No |
| LA | Gas valve operation fault | Reset boiler | No |
| LE | Flame sensor fault | Reset boiler | No |
| Code | Meaning | Quick Fix | DIY? |
|---|---|---|---|
| F4 | Overheat - limit stat triggered | Let boiler cool, check radiators are on, bleed air from system | Partial |
| F5 | Overheat - temperature limiter tripped | Let boiler cool, check circulation | Partial |
| F7 | Flow thermistor fault | Reset boiler | No |
| F8 | Return thermistor fault | Reset boiler | No |
| F9 | DHW thermistor fault | Reset boiler | No |
| F2 | Temperature rise too fast | Check circulation, bleed radiators | Partial |
| F3 | Temperature difference too great | Check circulation, pump operation | Partial |
| Code | Meaning | Quick Fix | DIY? |
|---|---|---|---|
| L6 | Fan speed fault - not reaching required RPM | Reset boiler, check flue terminal is clear of debris | No |
| L7 | Air pressure switch open | Reset boiler, check flue is not blocked | No |
| L8 | Air pressure switch closed | Reset boiler | No |
| LF | Flue temperature sensor fault | Reset boiler | No |
| Code | Meaning | Quick Fix | DIY? |
|---|---|---|---|
| LC | PCB communication fault | Reset boiler | No |
| LD | Display PCB fault | Reset boiler | No |
| LB | RF communication fault (wireless controls) | Check thermostat batteries, reset boiler | Partial |
| FC | Pump operation fault | Check pump is working, reset | No |
| FB | Diverter valve fault | Reset boiler | No |
Most Ideal boilers can be reset by pressing the reset button:
Important: If the fault returns after resetting, do NOT keep resetting repeatedly. This can damage the boiler. Call a Gas Safe engineer.
Our Gas Safe engineers service all Ideal models across Harrow and London.