BoilerFaultCodesBaxi 4 flashes red Fault Code
Also written as 4FLASHESRED — same fault.
The Baxi 4 flashes red fault code means: your boiler's fan, which safely pushes exhaust gases out of the flue, is not spinning at the correct speed or has stopped working entirely.. It appears on 11 Baxi models in our database.
Technical description: Fan fault: Fan calibration error, Fan failure
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 4 flashes red: no call-out fees, no surprise bills.
Affiliate links. We may earn a commission at no extra cost to you.
Baxi models that show the 4 flashes red fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Baxi 4 flashes red fault code information on this page is sourced and cross-checked against the official Baxi service / installation manuals for each affected model.
Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 31 August 2026