BoilerFaultCodesTechnical description
50 Hz ERROR The mains frequency is not 50 Hz
What causes this fault?
This fault occurs when the boiler's internal sensors detect that the incoming electrical supply is not stable enough to run the electronic components safely. The most common reasons are fluctuations in the National Grid supply or issues with your home’s electrical wiring, though it can also be triggered if the boiler’s main control board has developed a fault and is misreading the power signal.
This fault is more common during periods of extreme weather, such as heavy storms or heatwaves, which can put the local electrical grid under stress and cause supply instability.
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.