Ideal
Classic FF 240
Regular
12kW
1988-2000
ErP D
77 fault codes
<p>The Classic FF 240 is a combi boiler from Ideal, available at 12kW output. Produced 1988-2000.</p>
Classic FF 240 Fault Codes 77
Code
Description
Severity
Type
C0
Fan Fault — Fan Not Running
The fan has failed to start or is not reaching operating speed. C0 is a lockout…
High
Engineer
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C0 0
Fan Not Running at Start (Sub-code)
The fan is not running at the point in the start sequence where it is required.
High
Engineer
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C1
Flue Temperature Too High
The flue gas temperature has exceeded the safe limit. The boiler has shut down to prevent…
High
Engineer
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C2
Fan Fault — Speed Out of Range
The fan speed is outside the expected operating range — either too slow or too fast.
High
Engineer
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C3
Air Pressure Switch Open
The air pressure switch is not closing when the fan runs. The boiler cannot confirm adequate…
High
Engineer
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C5
Rapid Temperature Rise
Flow temperature rising too quickly, indicating poor circulation.
High
Engineer
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C6
Flow/Return Differential Too Large
The temperature gap between flow and return is abnormal.
Medium
Engineer
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F1
Low Water Pressure
The boiler's water pressure has dropped below the minimum operating level. One of the most common…
Low
DIY
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F10
DHW Temperature Sensor Fault
The domestic hot water temperature sensor has a fault. On combi boilers, this prevents safe hot…
Medium
Engineer
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F11
Cylinder Sensor Fault
The hot water cylinder temperature sensor has a fault. Relevant on system boilers paired with a…
Medium
Engineer
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F12
Flame Loss During Operation
The boiler had a stable flame but lost it during operation. This can be caused by…
High
Engineer
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F13
Gas Pressure Sensor Fault
The gas pressure sensor is giving an out-of-range reading, preventing safe operation.
High
Engineer
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F14
Gas Valve Fault
The gas valve is not responding correctly to commands from the PCB.
High
Engineer
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F15
PCB Communication Fault
The printed circuit board (PCB) has an internal communication error. Key boiler components cannot communicate correctly.
High
Engineer
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F16
Fan Fault
The fan is not running at the correct speed or has stopped. The boiler cannot safely…
High
Engineer
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F17
Pump Over-Run Fault
The pump did not stop after the burner shut down.
Medium
Engineer
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F2
Flame Loss
The boiler has lost its flame during operation or failed to ignite.
Medium
DIY
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F20
Pressure Sensor Fault
The electronic water pressure sensor is giving incorrect readings.
Medium
Engineer
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F3
Fan Fault
The boiler fan is not operating at the required speed, preventing safe ignition.
High
Engineer
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F4
Flow Thermistor Fault
The flow temperature sensor (thermistor) is giving an incorrect reading or has failed.
Medium
Engineer
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F5
Return Thermistor Fault
The return temperature sensor is giving an incorrect reading or has failed.
Medium
Engineer
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F6
Outside Sensor Fault
The external temperature sensor (used for weather compensation) is faulty or not connected. This does not…
Low
Engineer
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F7
Low Mains Voltage
The mains voltage supply to the boiler has dropped below the safe minimum (185V).
Medium
Engineer
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F8
Flow Thermistor - Out of Range High
The flow temperature sensor is reading higher than its maximum expected value, indicating a sensor fault…
High
Engineer
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F9
Unconfigured PCB
The Printed Circuit Board has not been configured correctly. This almost always occurs after a PCB…
Medium
Engineer
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FA
Flow/Return Sensors Reversed (Regular Boilers)
On Ideal Logic Max and Logic Plus regular (heat-only) boilers, code FA indicates the flow and…
Medium
Engineer
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FD
Condensate Blocked / Frozen
The condensate drain system is blocked or frozen. FD is Ideal's code for a blocked condensate…
Medium
DIY
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FN
Flame Loss (Alternative Code)
On some Ideal models, FN is displayed alongside or instead of F2 to indicate flame loss…
Medium
DIY
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FU
Temperature Difference Too High — Check Isolation Valves
The temperature difference between the flow and return is greater than 50°C. The boiler is blocking…
Medium
DIY
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GV
Gas Valve Fault
The gas valve is not responding to commands from the PCB.
High
Engineer
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HT
DHW Overheat
The domestic hot water temperature has exceeded safe limits.
High
Engineer
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L0
Safety Limit Lockout (Generic)
A safety device has operated. This is a catch-all lockout code when a specific fault cannot…
High
Engineer
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L1
Flow Overheat / No Water Flow Lockout
The boiler has locked out because the flow temperature is too high or no water is…
High
Engineer
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L10
Overheat Lockout — Maximum Temperature Exceeded
The boiler has reached its absolute maximum temperature and locked out. A more severe overheat than…
High
Engineer
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L11
Central Heating Thermistor Fault
The central heating NTC thermistor is reading outside its normal range. The sensor may have developed…
Medium
Engineer
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L2
Ignition Lockout
The boiler has locked out after failing to ignite or losing its flame. A persistent version…
Medium
DIY
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L3
Fan Lockout
The boiler fan has failed to reach the required speed after multiple attempts.
High
Engineer
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L4
Overheat Lockout
The boiler's safety overheat thermostat has triggered a lockout due to excessively high temperatures.
High
Engineer
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L5
Too Many Resets
The boiler has been reset 5 times within 15 minutes and has entered a protective lockout.
Medium
DIY
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L6
False Flame Lockout
The boiler has detected an ionisation signal when the gas valve should be closed. This is…
High
Engineer
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L7
DHW Thermistor Lockout
The domestic hot water temperature sensor has caused a lockout — either due to a sensor…
High
Engineer
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L8
Flue Temperature Lockout
The flue gas temperature sensor has detected an unsafe temperature, causing a lockout.
High
Engineer
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L9
PCB Fault / Unconfigured
The PCB has an internal fault or has not been configured correctly. L9 is the lockout…
High
Engineer
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LC
Too Many Resets (5 Within 15 Minutes)
The boiler has been reset 5 or more times within 15 minutes and has entered a…
Medium
DIY
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LF
Low Gas Pressure Warning
The boiler has detected that the gas supply pressure is lower than expected, which may cause…
Medium
Engineer
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LN
Flame Loss Lockout (Alternative Code)
On some Ideal models, LN is a lockout version of FN/F2, indicating repeated flame loss requiring…
Medium
DIY
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SE
Sensor Error
One or more NTC temperature sensors are reading outside expected range.
Medium
Engineer
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