BoilerFaultCodesIdeal J46 Fault Code
The Ideal J46 fault code means: your heat pump’s internal power control system has encountered a fault, meaning the outdoor unit cannot currently run to provide heating or hot water.. It appears on 1 Ideal model in our database.
Technical description: Inverter Error
What causes the Ideal J46 fault?
This fault occurs when the internal power management system, known as the inverter, stops communicating correctly with the main computer of the heat pump. The most common reason is an electrical failure within the inverter circuit board due to power surges or component wear, which prevents the unit from controlling the fan and compressor speed.
This fault can be more frequent during summer or extreme heatwaves, as high ambient temperatures put additional thermal stress on the electronic power components.
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 J46 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Ideal J46 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