BoilerFaultCodesAlpha Primary flow switch operated Fault Code
Also written as PRIMARYFLOWSWITCHOPERATED — same fault.
The Alpha Primary flow switch operated fault code means: your boiler detects water movement even when it is not supposed to, which often means an internal valve is stuck or a sensor is misreading the flow.. It appears on 1 Alpha model in our database.
Technical description: Follow section 'C' fault finding
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
Find a Gas Safe engineer
Search the official register for a qualified engineer in your area.
Gas Safe Register →Avoid the next call-out bill
A cover plan would handle faults like Primary flow switch operated: no call-out fees, no surprise bills.
Affiliate links. We may earn a commission at no extra cost to you.
Alpha models that show the Primary flow switch operated fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Alpha Primary flow switch operated fault code information on this page is sourced and cross-checked against the official Alpha service / installation manuals for each affected model.
Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 7 July 2026