BoilerFaultCodesYour boiler has switched itself off because it has detected air bubbles trapped in the system or a lack of water flow, which is causing it to overheat too quickly.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Boiler shut down due to air passing through the pump or system not correctly vented (monitors temperature rise across the heat exchanger).
What causes this fault?
This fault occurs when air enters the internal pipework or the water stops moving quickly enough, causing the heat exchanger to reach high temperatures too fast. The most common reason is trapped air bubbles passing through the pump or a pump that is beginning to fail and can no longer push water through the boiler effectively.
This fault is frequently seen in autumn when heating systems are turned back on after summer, as air often settles in the radiators and pipework during the period of disuse.
DIY fix possible
Check the pressure gauge and top up to 1.5 bar if it is lowTurn off the boiler and bleed all radiators to remove trapped airEnsure all radiator valves and the boiler isolation valves are fully openRestart the boiler to see if the code clears
Find a Gas Safe engineer
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A boiler cover plan would cover faults like E14 — no call-out fees, no surprises.
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Potterton Envoy 30 is discontinued — time for a new one?
Parts for discontinued models can be hard to find and expensive. A new A-rated boiler could save you money on both repairs and energy bills.
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