BoilerFaultCodesWhat the manual says
Manufacturer manualpump has run dry
From this model's manual
Verified against the Worcester Bosch Greenstar 25he installation & service manual.
What causes this fault?
This fault occurs when the boiler's internal pump is spinning but is unable to move water through the heat exchanger. The most common reasons are a lack of water pressure in the system, a large pocket of air trapped inside the pump, or a physical failure of the pump motor itself.
This fault often appears in autumn when the heating is turned back on for the first time, as pump components can seize or become stuck during months of inactivity.
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.
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