BoilerFaultCodesIdeal Safety temperature limiter Fault Code
Also written as SAFETYTEMPERATURELIMITER — same fault.
The Ideal Safety temperature limiter fault code means: your boiler has switched itself off because the water inside became too hot, likely due to a circulation issue.. It appears on 1 Ideal model in our database.
Technical description: Operates if the water flow rate through the boiler is inadequate; requires manual reset by pushing in the 'reset' button.
What causes the Ideal Safety temperature limiter fault?
This fault occurs when the water inside the boiler exceeds a safe operating temperature, triggering a safety shut-off to prevent damage. It is usually caused by a blockage in the system or a failing pump that is no longer moving hot water away from the heat exchanger quickly enough. In some cases, the internal sensor responsible for monitoring heat may have developed a fault and is providing an incorrect reading.
This issue often surfaces when the heating is first turned on after summer, as pump components can seize during long periods of inactivity.
DIY fix possible
Locate the manual reset button on the control panelFirmly push the reset button in to restart the systemCheck that all radiator valves are open and the pump is running
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Gas Safe Register →Ideal models that show the Safety temperature limiter fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Ideal Safety temperature limiter 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