BoilerFaultCodesIdeal 9.1.11 Fault Code
Also written as 9111 — same fault.
The Ideal 9.1.11 fault code means: your heat pump's outdoor unit has detected a problem with the sensor that monitors the temperature of the refrigerant gas as it leaves the compressor, causing the system to stop running to prevent damage.. It appears on 1 Ideal model in our database.
Technical description: Outdoor Unit, Discharge Thermistor (Tp) Error
What causes the Ideal 9.1.11 fault?
This fault occurs when the control system receives an incorrect or missing signal from the sensor that monitors the heat of the refrigerant gas. It often happens because the sensor has failed internally, or because the electrical wiring connecting it to the main circuit board has become loose or damaged. To prevent the unit from overheating and causing expensive internal damage, the system safely shuts itself down.
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 9.1.11 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Ideal 9.1.11 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