Baxi · Combi & System 2 platform
E.02.39Minimum pressure not reached after six minutes of automatic filling
This code applies to Baxi 200 Combi 2, Baxi 400 Combi 2, Baxi 600 Combi 2, Baxi 800 Combi 2, Baxi Assure 500 Combi 2, Baxi 600 System 2, Baxi 800 System 2, Baxi Assure 500 System 2. Fault codes narrow down the likely problem, but they do not replace a model-specific diagnosis.
What you can safely check
- Check the pressure gauge with the system cold.
- If it is below the range stated in the boiler manual, repressurise only by following that model's user instructions.
- Stop and book an engineer if pressure drops again, rises excessively, or there is a visible leak.
How an engineer may fix it
Check for leaks, trapped air, the pressure sensor, pump and expansion vessel; repair the underlying fault before recommissioning.
Manufacturer source: Baxi Professional — Boiler Error Codes. Checked 15 August 2026. The appliance manual and an engineer’s on-site diagnosis take precedence. Never remove the boiler case yourself.