BoilerFaultCodesBritish Gas F6 Fault Code
The British Gas F6 fault code means: your boiler is struggling to read the temperature of the water flowing to your radiators, so it has turned itself off to prevent overheating.. It appears on 1 British Gas model in our database.
Technical description: Central Heating Flow Thermistor connection fault (displayed as 'Fntc')
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
Find a Gas Safe engineer
Search the official register for a qualified engineer in your area.
Gas Safe Register →Avoid the next call-out bill
A cover plan would handle faults like F6: no call-out fees, no surprise bills.
Affiliate links. We may earn a commission at no extra cost to you.
British Gas models that show the F6 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
British Gas F6 fault code information on this page is sourced and cross-checked against the official British Gas service / installation manuals for each affected model.
Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 7 July 2026