Ideal 9.1.6 Fault Code
Also written as 916 — same fault.
The Ideal 9.1.6 fault code means: your heat pump has stopped providing hot water because a sensor that monitors the water temperature has developed a fault or is disconnected.. It appears on 1 Ideal model in our database.
Technical description: DHW Thermistor (T5) Error
What causes the Ideal 9.1.6 fault?
This fault occurs when the heat pump loses communication with the sensor monitoring the temperature inside your hot water cylinder. The most common reason is that the sensor has failed internally due to wear, or the wiring connecting it to the main control board has become loose or damaged.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
Find a Gas Safe engineer
Search the official register for a qualified engineer in your area.
Gas Safe Register →Ideal models that show the 9.1.6 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Ideal 9.1.6 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