Your boiler has shut down because it is unable to accurately measure the air pressure required for its burner to operate safely.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Burner blocked. Differential pressure sensor faulty. Cause: Check the differential pressure sensor and lead.
What causes this fault?
This fault occurs when the boiler's internal computer receives an incorrect or missing signal from the sensor that monitors air flow. The most common cause is a physical blockage in the burner or a failure in the electronic sensor that ensures the unit is breathing correctly for safe combustion.
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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A boiler cover plan would cover faults like F7 — no call-out fees, no surprises.
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Viessmann Vitodens 333 is discontinued — time for a new one?
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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