BoilerFaultCodesYour boiler has sensed it is getting too hot too quickly and has shut down to protect its internal parts from damage.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Exchanger protection activation – possibly caused by no system circulation, air in the system or sensor damaged
What causes this fault?
This fault occurs when the boiler's internal components detect a rapid, unsafe rise in temperature that cannot be dissipated. It is usually caused by a blockage in the pipework, a buildup of air, or a pump that has failed and stopped moving water through the system. In some cases, the temperature sensor itself may be faulty and providing an incorrect reading to the control board.
This issue often surfaces when the heating is first turned on after summer, as circulation pumps can seize up during long periods of inactivity.
DIY fix possible
Check that your radiator valves are open and not turned to the off position.Ensure the boiler pressure is between 1.0 and 1.5 bar on the pressure gauge.Try bleeding your radiators to remove any trapped air that might be blocking water flow.
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A boiler cover plan would cover faults like F39 — no call-out fees, no surprises.
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Ferroli Modena HE 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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