Technical description
Compressor Stall Error
What causes this fault?
This fault occurs when the main pump inside the unit attempts to start but is physically prevented from turning or maintaining its rhythm. The most common reasons are a mechanical failure within the pump itself, an electrical fault in the control board, or an issue with the components that provide the initial power boost to get the system running.
This issue is more frequent during the first cold snaps of autumn or winter when the system is required to work harder after long periods 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.