BoilerFaultCodesTechnical description
Flow temperature is higher than the set maximum temperature
What causes this fault?
This fault occurs when water cannot move through the boiler quickly enough to carry heat away, causing the internal temperature to reach a dangerous level. The most common reasons are a failed external pump that isn't pushing water to the radiators or a buildup of sludge and debris that has physically blocked the pipes or heat exchanger.
This issue often appears during the first cold spell of autumn when the heating is turned back on after sitting 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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