BoilerFaultCodesYour boiler is getting too hot too quickly, causing it to shut down for safety.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: higher flow temperature
What causes this fault?
This fault occurs when the water inside the boiler heats up faster than it can be pumped away, causing the system to overheat. The most common reasons are a failing circulation pump that isn't moving water fast enough or a buildup of limescale and sludge that is restricting flow through the heat exchanger.
This issue is more common during the first cold snap of autumn when central heating is turned back on after being dormant all summer, which often reveals a seized pump.
DIY fix possible
Check that all radiator valves are fully open to allow water to circulate.Ensure the central heating pump is running and hasn't become stuck.Gently bleed air from your radiators if you've noticed cold spots.
Find a Gas Safe engineer
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A boiler cover plan would cover faults like E — no call-out fees, no surprises.
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Potterton Envoy 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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