BoilerFaultCodesIdeal LC5 Fault Code
The Ideal LC5 fault code means: your heat pump has stopped working because of a communication or electrical fault in the main power control unit.. It appears on 1 Ideal model in our database.
Technical description: Inverter Error
What causes the Ideal LC5 fault?
This fault occurs when the internal brain of the heat pump loses the ability to manage the power sent to the compressor. It is usually caused by a failure in the electrical components that convert power, or a breakdown in communication between the main control boards. Effectively, the system can no longer safely regulate the energy needed to run the outdoor unit.
This error is more frequently seen during peak summer or winter months when the heat pump is working hardest and electrical components are under the most thermal stress.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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Gas Safe Register →Ideal models that show the LC5 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Ideal LC5 fault code information on this page is sourced and cross-checked against the official Ideal service / installation manuals for each affected model.
Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 27 April 2026