BoilerFaultCodesIdeal 919 Fault Code
The Ideal 919 fault code means: your boiler has switched itself off because the water returning to the unit is too hot, meaning the heat isn't being distributed around your home properly.. It appears on 2 Ideal models in our database.
Technical description: Maximum temperature - Return temperature T2 too high
What causes the Ideal 919 fault?
This fault occurs when the water returning to the boiler is almost as hot as the water leaving it, indicating that heat is not being transferred into your radiators or cylinder. The most common reason is a failure of the external pump or a blockage in the pipework that prevents the water from circulating through your heating system. It can also be caused by all your radiator valves being closed at the same time, leaving the hot water with nowhere to go.
This fault is more common in autumn when heating systems are turned back on after a long summer break, as external pumps can seize up due to inactivity.
DIY fix possible
Ensure all radiator valves (TRVs) are fully open to allow water to circulateCheck that your external pump (if applicable) is running and hasn't seizedInspect the system's bypass valve to ensure it isn't closed or blocked
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Gas Safe Register →Ideal models that show the 919 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Ideal 919 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