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 10 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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A cover plan would handle faults like Overheat LOCKOUT: no call-out fees, no surprise bills.
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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.
- Performa SL HE 9 2 Repair: £120-250
- Promax 15/2 HE Plus Repair: £150-300
- Promax 24/2 HE Plus Repair: £150-300
- Promax 30 HE Plus Repair: £150-300
- Promax FSB 30HE Repair: £150-300
- Promax Heat Only Repair: £120-250
- Promax SL 12 Heat ErP Repair: £150-300
- Promax SL 18 Heat ErP Repair: £150-300
- Promax SL 24 Heat ErP Repair: £150-300
- Suprima HE Repair: £120-250
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 Promax 30 HE Plus manual (PDF)
- Potterton Promax FSB 30HE manual (PDF)
- Potterton Promax Heat Only manual (PDF)
Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 31 August 2026