BoilerFaultCodesIdeal H2 Fault Code
The Ideal H2 fault code means: your heat pump has stopped working because a sensor that monitors the temperature of the internal heating fluid has developed a fault.. It appears on 1 Ideal model in our database.
Technical description: Plate Heat Exchanger Outlet Refrigerant Thermistor (T2) Error
What causes the Ideal H2 fault?
This fault occurs when the system's internal control board loses the ability to read the temperature from a specific sensor on the heat exchanger. This usually happens because the sensor itself has failed due to wear and tear, or because the electrical wiring connecting it to the brain of the unit has become loose or damaged.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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Ideal models that show the H2 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Ideal H2 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 7 July 2026