BoilerFaultCodesIntergas F003 Fault Code
The Intergas F003 fault code means: your boiler has shut down because the internal gases leaving the system have become too hot, which is a safety feature to prevent damage to the internal components.. It appears on 5 Intergas models in our database.
Technical description: Flue gas temperature too high
What causes the Intergas F003 fault?
This fault occurs when the internal safety sensor detects that the exhaust gases have reached a dangerously high temperature, often due to a lack of water flow or a build-up of debris inside the heat exchanger. It essentially means the heat being produced isn't being carried away into your radiators efficiently enough, causing the internal components to overheat. In some cases, it can also be triggered by a faulty sensor providing an incorrect reading or damaged internal insulation.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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Gas Safe Register →Intergas models that show the F003 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Intergas F003 fault code information on this page is sourced and cross-checked against the official Intergas service / installation manuals for each affected model.
Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 27 April 2026