BoilerFaultCodesWhat the manual says
Manufacturer manualpump has run dry
What causes this fault?
This fault occurs when the boiler's internal sensors detect air pockets or a significant drop in water pressure, preventing the pump from moving water around. The most common cause is a leak in the system or radiators that have recently been bled, leaving the boiler with insufficient water to operate safely. Without enough water to act as a lubricant and coolant, the pump 'runs dry' and the system shuts down to prevent heat damage.
This issue is frequently seen in autumn when homeowners turn their heating back on for the first time and discover pressure has dropped over the summer months.
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.
Avoid the next call-out bill
A cover plan would handle faults like A1: no call-out fees, no surprise bills.
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Related fault codes
All 25 fault codes on the Greenstar 30HE
Seeing a different code? Every code this model can display, in one place.