BoilerFaultCodesYour boiler has stopped working because it cannot safely clear waste gases through the flue pipe.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Differential fan pressure status
What causes this fault?
This fault occurs when the boiler's internal safety sensors detect that the fan isn't moving enough air to safely vent exhaust gases outside. The most common reasons are a build-up of dirt or debris in the small plastic tubes inside the unit, or the fan motor itself failing after years of heavy use.
This issue is more common during the first cold snaps of autumn when a fan that has been idle over summer is suddenly required to run at high speeds.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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A boiler cover plan would cover faults like 669 — no call-out fees, no surprises.
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Worcester Bosch WR325 RSF 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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