BoilerFaultCodesTechnical description
Test program where the appliance is operated in full load after successful ignition
What causes this fault?
This is not actually a fault, but a built-in safety and performance check. It occurs because the boiler needs to confirm it can safely reach its highest firing rate immediately after the burners have lit. Once the system satisfies itself that everything is venting and heating correctly at full power, the code will disappear and normal operation will resume.
DIY fix possible
Wait for the test to complete automaticallyDo not turn the boiler off while the code is displayedMonitor the display to ensure it returns to a normal temperature reading
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