BoilerFaultCodesTechnical description
Fault codes 7x appear if a problem exists with the flow temperature (2nd CH).
What causes this fault?
This fault occurs when the boiler's internal sensors detect that the water is heating up too quickly or reaching dangerous temperatures without being moved away. The most common reasons are a pump that has stopped circulating water or a blockage in the system, causing the heat to build up inside the unit rather than being sent to your radiators.
This issue is more frequent in autumn when heating systems are switched back on after being idle all summer, which can cause internal pump parts to seize.
Engineer required
This is a high severity fault. Stop using the boiler and call a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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