BoilerFaultCodesWhat the manual says
Manufacturer manualStatus external heating pump error
What causes this fault?
This fault occurs when the boiler sends a signal to an external pump but does not receive the necessary feedback to confirm it is working. The most common reasons are a mechanical failure within the pump itself, a loose connection in the wiring, or a communication error within the main control board. Without this pump operating correctly, the boiler cannot safely move heat away from its internal heat exchanger.
This fault is more common in autumn when heating systems are switched back on after being idle all summer, which can cause external pumps to seize.
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 D,11: no call-out fees, no surprise bills.
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