BoilerFaultCodesYour boiler is detecting an issue with the quality or frequency of the electricity coming from your mains supply, causing the system to shut down for safety.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Electrical supply not 50Hz. Correct the electrical supply
What causes this fault?
This fault occurs when the boiler's internal computer detects that the incoming electrical current is unstable or at the wrong frequency. Common reasons include a failing motherboard that can no longer read the power supply correctly, or external interference from heavy machinery and portable generators nearby. In some cases, a fault with the street-level power grid or local electrical work can cause the supply to fluctuate enough to trigger this safety shutdown.
This fault is more common during the winter months when high demand on the national grid can lead to localized voltage drops or 'brownouts'.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
Find a Gas Safe engineer
Search the official register for a qualified engineer in your area.
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