BoilerFaultCodesYour boiler has temporarily paused operation because it has detected an unusual reading and is waiting for the condition to clear or for a manual reset.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Blocking Error
What causes this fault?
This fault occurs when the boiler's internal computer receives an unconventional signal from the burner sensors during the ignition or heating process. The most common reason is a failure to properly detect a flame, which triggers a safety pause to prevent unburnt gas from building up in the system.
DIY fix possible
Locate the reset button or dial on the control panelPress and hold the reset button for five seconds then releaseWait for the boiler to attempt to restart; if the code returns, contact a professional
Find a Gas Safe engineer
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Parts for discontinued models can be hard to find and expensive. A new A-rated boiler could save you money on both repairs and energy bills.
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