Ideal Heating has been providing reliable central heating for over 100 years, but no matter how good your boiler is, from time to time, it will display an error code to alert you that it is not functioning as well as it could.
Some error codes highlight problems that are easy to fix, while others need to be sorted out by a Gas Safe registered engineer.
Here are some of the most common fault codes that occur with Ideal boilers to help you determine how best to resolve them.
Common Ideal Logic Boiler Fault or Error Codes
| Fault code | System behaviour |
| 0 | The boiler is in standby mode awaiting either a central heating call or hot water demand |
| C | The boiler has a call for central heating but the appliance has reached the desired temperature set on the boiler OR The boiler is operating in hot water mode |
| C0 | Boiler chip card (BCC) activation fault |
| C2 | Boiler chip card (BCC) fault |
| d | The boiler is operating in hot water mode |
| D | The boiler has a call for hot water but the appliance has reached the desired
temperature set on the boiler |
| F | The boiler is operating in frost mode |
| F1 | Low water pressure |
| F2 | Flame loss |
| F3 | Fan fault |
| F4 | Flow thermistor fault |
| F5 | Return thermistor fault |
| F6 | Outside sensor failure |
| F7 | Low mains voltage |
| F9 | Unconfigured printed circuit board (PCB) |
| L1 | Flow temperature overheat or no water flow |
| L2 | Flame loss |
| L5 | 5 boiler resets in 15 minutes |
| L6 | False flame lockout |
Ideal Logic Max System / Logic plus system boiler fault or error codes
| Fault code | System Behaviour |
| L1 | Flow temperature overheat lockout or no water flow lockout |
| L2 | Ignition lockout |
| LC | Turn power off and on |
| L6 | False flame lockout |
| F1 | Low water pressure |
| F2, FN or LN | Flame loss |
| F3 | Fan fault |
| L4 or F4 | Control / no flow thermistor fault |
| L5 or F5 | Return thermistor fault |
| F6 | Outside sensor fault |
| F7 | Low mains voltage. Contact electricity provider |
| F9, L9, F8 or L8 | Printed circuit board (PCB) unconfigured or fault |
| FU | Diff greater than 50c check isolation valves are open |
| No central heating | Boiler problems? Book a boiler engineer now |
| No hot water | |
| No display |
Ideal Logic Max / Logic Plus regular boiler error codes
| Fault code | System Behaviour |
| L1 | Flow temperature overheat lockout or no water flow lockout |
| L2 | Ignition lockout |
| LC | 5 restarts within 15 minutes |
| L6 | False flame lockout |
| FA | Flow return reversed |
| FD | No water flow |
| F2 or FN or LN | Flame loss |
| F3 | Fan Fault |
| L4 or F4 | Control / no flow thermistor fault |
| L5 or F5 | Return thermistor fault |
| F6 | Outside sensor fault |
| F7 | Low mains voltage contact electricity provider |
| F9, L9, F8 or L8 | Printed circuit board (PCB) unconfigured or fault |
| FU | Diff greater than 50c check isolation valves are open |
| No central heating |
Boiler problems? Contact us now
|
| No hot water | |
| No display |
Ideal logic max plus combi boiler error codes
| Fault description | System Behaviour |
| Overheat lockout | Bleed radiators, refill system to 1.2 bar. Check that all radiator and boiler valves are open and reset boiler. |
| Ignition lockout | Check gas appliances work and restart boiler |
| Too many restarts | 5 starts within 15 mins. Turn power on and off. |
| Flame on before gas on | False flame lockout. |
| Water pressure | With boiler off and system cold fill system to 1.0 bar and bleed radiators if fault continues,Visit our Quick Quote page for a professional assessment and boiler repair estimate. |
| Too many resets | 5 restarts within 15 minutes |
| Flame on before gas valve on | Flame on before gas valve is on |
| Low mains voltage | Less than 185v to boiler then check voltage at boiler mains in if mains voltage is okay, pump needs replacing |
| Low water pressure | Low water pressure |
| Flow return reversed | Check if the flow thermistor is correctly clipped to pipe. If not, replace flow
thermistor. |
| Printed circuit board (PCB) recently replaced | Reset boiler |
| Pump rotor blocked | Unblock pump |
| Flow temperature setpoint cannot be increased to 80c | Check flow and return thermistors securely clamped to piper check flow and return thermistor |
| Overheat lockout error | Boiler problems? Book an engineer. |
| Ignition lockout | |
| Flame loss | |
| Thermal fuse lockout | |
| Outside sensor fault | |
| Return thermistor | |
| Fan fault | |
| Printed circuit board (PCB) error | |
| No domestic hot water working | |
| Not hot water but central heating working | |
| No water flow fault |
If you’re dealing with Ideal Logic boiler problems, our fault code guide is a great resource. For additional insights into similar boiler issues, see our post on Worcester fault code E9.
