What the manual says
Manufacturer manualStart fan speed
What causes this fault?
This fault occurs when the boiler's control system attempts to start the fan but detects that it isn't reaching the necessary speed to safely vent exhaust gases. The most common reason is a mechanical failure within the fan motor or a communication error where the main circuit board cannot correctly read the fan's rotation speed.
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 9.d: no call-out fees, no surprise bills.
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Related fault codes
All 365 fault codes on the Greenstar CDi Compact
Seeing a different code? Every code this model can display, in one place.