BoilerFaultCodes.com

Ideal Logic Combi ESP1 Fault Codes

Combi Natural Gas 24-35 kW 2015-2022 Discontinued
GC Numbers: 47-348-9747-348-9847-348-99

Replaced by: Logic2 Combi

The fault code is already on your display

Note it down before pressing reset — resetting clears the code immediately. How to read fault codes →

Most common fault codes

F
Your boiler is alerting you to a specific problem, but the 'F' is just the prefix and requires the number that follows it to identify the actual issue.
Gas Safe engineer required · £100-£450
F1
Your boiler has stopped working because the water pressure inside the system has dropped too low to operate safely.
May be DIY safe · £0-120
F2
Your boiler has switched itself off because it started to light but the flame went out or could not be detected.
May be DIY safe · £100-£350

All 31 fault codes

Code Severity Plain English
C Low Your boiler is simply indicating that it is configured to operate as a 'Combination' boiler, which is a normal status message and not an actual fault.
DU Low Your boiler is currently in a manual service mode used for internal checks and is not indicating a broken part.
F High Your boiler is alerting you to a specific problem, but the 'F' is just the prefix and requires the number that follows it to identify the actual issue.
F1 High Your boiler has stopped working because the water pressure inside the system has dropped too low to operate safely.
F2 High Your boiler has switched itself off because it started to light but the flame went out or could not be detected.
F3 High Your boiler has stopped working because the internal fan, which safely exhausts gases produced during heating, is not running correctly.
F4 High Your boiler has likely stopped heating because a sensor that measures the temperature of the water leaving the unit has failed or become disconnected.
F5 High Your boiler's internal sensor that monitors the temperature of the water coming back into the unit has developed a fault, preventing the system from operating correctly.
F6 Low Your boiler is having trouble communicating with the optional sensor that measures the temperature outside, which may cause your heating to behave unpredictably.
F7 High Your boiler is not receiving enough electrical power from the grid to operate safely and has shut down as a precaution.
F8 High Your boiler's internal computer brain either hasn't been set up correctly or has developed a hardware failure, preventing the unit from starting.
F9 High Your boiler's main control board hasn't been set up correctly to tell it which model it is, so it doesn't know how to operate yet.
FA High Your boiler has detected that the temperature sensors are reading back-to-front or are failing, causing it to shut down for safety.
Fn High Your boiler has failed to maintain a flame, which means it has stopped providing heating and hot water to protect itself.
FU High Your boiler has detected that water is getting too hot too quickly because it isn't circulating through your radiators or pipes correctly.
L High Your boiler has switched itself off for safety and needs to be manually restarted to identify the specific fault.
L1 High Your boiler has shut down because the water inside it has become too hot, usually due to a lack of water flow or a circulation problem.
L2 High Your boiler has tried to light several times but cannot establish a flame, meaning it has shut down for safety.
L4 High Your boiler has detected a problem with the internal sensor that monitors the temperature of the water as it leaves the unit, causing the system to shut down as a safety precaution.
L5 High Your boiler has detected a problem with the sensor that monitors the temperature of the water returning to the unit, causing it to shut down for safety.
L6 High Your boiler thinks it sees a flame when there shouldn't be one, so it has shut down as a safety precaution.
L8 High Your boiler's internal computer brain either isn't set up correctly or has developed a technical hardware fault, preventing the unit from starting.
L9 High Your boiler’s main computer chip has forgotten its settings or has developed an internal electrical failure, meaning the unit cannot function.
LC High Your boiler is repeatedly failing to start and has locked itself out for safety after five unsuccessful attempts in a short period.
Ln High Your boiler is struggling to keep its flame lit, which means it cannot heat your water or radiators.
n Low Your boiler is simply displaying a status code to confirm it is configured to run on Natural Gas; this is not a fault and requires no action.
oF Medium Your boiler is currently stuck in a technical programming mode used by engineers and is not currently in its normal operating state.
SH Low Your boiler is currently in service mode, which is an intentional setting used by engineers to test the system and not a mechanical breakdown.
SL Low Your boiler is not actually broken; it is currently in a manual service mode used by engineers to test the system or displays a history of recent issues.
UF Low Your boiler is currently in a manual testing or service mode used by engineers and is not actually reporting a breakage or fault.
uP High Your boiler is currently stuck in its internal computer programming mode and hasn't been set up to operate as a heater yet.

Ideal Logic Combi ESP1 is discontinued — time for a new one?

Parts for discontinued models can be hard to find and expensive. A new A-rated boiler could save you money on both repairs and energy bills.

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