BoilerFaultCodesIdeal Overheat thermostat lockout Fault Code
Also written as OVERHEATTHERMOSTATLOCKOUT — same fault.
The Ideal Overheat thermostat lockout fault code means: your boiler has detected that it got too hot and has automatically shut itself down to prevent internal damage.. It appears on 6 Ideal models in our database.
Technical description: Overheat thermostat lockout
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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Ideal models that show the Overheat thermostat lockout fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Ideal Overheat thermostat lockout 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 7 July 2026