BoilerFaultCodesIdeal 912 Fault Code
The Ideal 912 fault code means: your boiler has shut down because it believes the internal water pressure is too low or it is getting too hot inside.. It appears on 3 Ideal models in our database.
Technical description: Water pressure switch or flue thermostat failure
What causes the Ideal 912 fault?
This fault occurs when the boiler's safety sensors detect that there isn't enough water pressure to operate safely or that the internal exhaust gases are reaching dangerous temperatures. It is often caused by a leak in the system, a failing pressure sensor, or an internal component like the expansion vessel losing its air charge. When these conditions are met, the boiler shuts down immediately to prevent serious damage to the heat exchanger.
This issue is frequently seen in autumn when homeowners turn their heating back on for the first time, as small leaks or loss of pressure over the summer months become apparent.
DIY fix possible
Check the pressure gauge on the front of the boilerIf the pressure is below 1 bar, use the filling loop to top it up to 1.5 barReset the boiler to see if the error clears
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Gas Safe Register →Ideal models that show the 912 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Ideal 912 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