BoilerFaultCodesPotterton Overheat LOCKOUT Fault Code
Also written as OVERHEATLOCKOUT — same fault.
The Potterton Overheat LOCKOUT fault code means: your boiler has detected that it has become too hot and has automatically shut itself down to prevent damage, requiring you to manually restart it.. It appears on 6 Potterton models in our database.
Technical description: Manual reset. The 'Lockout' (Red) light will flash. Occurs if an overheat condition occurs or the overheat stat is off.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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Potterton models that show the Overheat LOCKOUT fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Potterton Overheat LOCKOUT fault code information on this page is sourced and cross-checked against the official Potterton service / installation manuals for each affected model.
- Potterton Performa SL HE 9 2 manual (PDF)
- Potterton Promax 15/2 HE Plus manual (PDF)
- Potterton Promax FSB 30HE manual (PDF)
Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 7 July 2026