BoilerFaultCodesIdeal 4.7 Fault Code
Also written as 47 — same fault.
The Ideal 4.7 fault code means: your boiler has detected a problem with the internal sensor that measures the temperature of the water leaving the unit, preventing it from heating correctly.. It appears on 8 Ideal models in our database.
Technical description: Flow Thermistor Fault
What causes the Ideal 4.7 fault?
This fault occurs when the boiler's control board loses communication with the sensor that monitors the temperature of the water heading to your radiators. It is usually caused by the internal sensor failing due to age or heat fatigue, though it can also be triggered by a loose electrical connection or moisture damange to the wiring.
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 4.7 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Ideal 4.7 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