BoilerFaultCodesYour boiler has detected that the water in the third heating zone is becoming too hot, causing the system to shut down that specific area to prevent damage.
This fault should be looked at by a Gas Safe engineer within the next week or two. It may get worse if left.
Technical description: Overheating in zone 3
What causes this fault?
This fault occurs when the boiler's sensors detect an unsafe rise in water temperature specifically within the third heating zone of your system. The most common reasons are a motorised zone valve that has failed to open, a blockage in that section of pipework, or a pump that isn't circulating the water quickly enough to carry heat away from the heat exchanger.
This issue often surfaces at the start of autumn when the heating is turned on for the first time after summer, as internal valve parts can seize up during long periods of inactivity.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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