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Ideal Fault Codes
Select a fault code to see its meaning, common causes and how to fix it.
Logic, Vogue & Evomax fault codes (L-series)
- L1 The L1 fault code on an Ideal boiler indicates that the boiler has detected an out-of-range flow temperature and has… Read more →
- L2 Ignition lockout — the boiler has tried to light but failed to detect a flame, so it has locked out for safety. Read more →
- L3 The L3 fault code appears on Ideal Logic and related boiler ranges as a safety lockout signal. In the majority of cases… Read more →
- L4 The L4 fault code on Ideal boilers indicates that the boiler's control system has detected a problem with the flow… Read more →
- L5 The L5 code is a safety lockout on Ideal boilers that covers two closely linked problems. Most commonly, it means the… Read more →
- L6 The L6 code appears on Ideal boilers when the boiler's flame detection electrode registers a flame signal at a moment… Read more →
- L8 The L8 fault code on Ideal boilers signals a problem with the Printed Circuit Board (PCB) — either the board itself has… Read more →
- L9 The L9 code is a lockout fault on Ideal boilers, but its precise meaning shifted as the range evolved over the years.… Read more →
- LA The code 'LA' does not appear in Ideal's standard published fault-code library. On Ideal boilers the display alternates… Read more →
- LC The LC fault code (also shown as L5 on some Ideal models) appears when your boiler has locked out and been manually… Read more →
- LF The LF fault code on Ideal boilers indicates an ignition failure. The boiler has attempted to light the burner one or… Read more →
- LN The LN fault code on an Ideal boiler signals that the control board has detected a loss of burner flame — either the… Read more →
Other fault codes (F, C & H-series)
- C0 The C0 code appears on Ideal boilers when the Boiler Chip Card (BCC) has failed to activate correctly. The BCC is a… Read more →
- C2 The C2 fault code on an Ideal boiler points to an internal error with the Boiler Chip Card (BCC) — a small device that… Read more →
- F1 On Ideal boilers, F1 means the appliance has detected low water pressure in the heating system and has shut itself down… Read more →
- F2 The F2 fault code on Ideal boilers indicates that the boiler either failed to establish a stable flame during ignition… Read more →
- F3 The F3 code on an Ideal boiler signals a problem with the flue fan. The fan's job is to push combustion gases safely… Read more →
- F4 The F4 code — also displayed as L4 on certain Ideal models — indicates that the boiler has detected a problem with its… Read more →
- F5 The F5 fault code on an Ideal boiler indicates a problem with the return thermistor — the sensor that measures the… Read more →
- F6 The F6 fault code on Ideal boilers signals a problem with the outdoor temperature sensor. When this code appears, the… Read more →
- F7 The F7 code on an Ideal boiler means the appliance has detected that the incoming mains voltage has dropped below… Read more →
- F8 The F8 fault code on Ideal boilers signals a problem with the Printed Circuit Board (PCB) — either the board itself has… Read more →
- F9 The F9 fault code on an Ideal boiler signals an electronic control or circulation problem. Depending on the specific… Read more →
- FA The FA fault code on Ideal boilers indicates that the boiler has detected a reversed flow and return condition. In a… Read more →
- FD The FD fault code on an Ideal boiler means the boiler's controls have detected insufficient water flow through the heat… Read more →
- FL The FL fault code (sometimes displayed as F/L or LF) on Ideal boilers indicates that the boiler's control board has… Read more →
- FN The FN fault code on an Ideal boiler indicates that the flame has been lost during operation. The boiler's PCB (printed… Read more →
- FU The FU fault code means your Ideal boiler has detected a temperature difference of more than 50°C between its flow pipe… Read more →
- H-3 The H-3 code appears on Ideal ISAR and ICOS combi boilers and signals a problem with the domestic hot water (DHW)… Read more →