Baxi · 400 Combi 2.1
A.02.06 boiler fault code
400 Combi 2.1
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What A.02.06 means
A.02.06 indicates low system pressure in the heating circuit.
Safe check
If there is no visible leak or suspected expansion-vessel fault, follow the Baxi 400 Combi 2.1 instructions to repressurise the heating circuit.
When to contact an engineer
A leak or suspected expansion-vessel fault needs a Gas Safe registered engineer; contact one if either is present or the pressure will not hold.
Safety notice
A boiler fault code alone is not a gas or carbon-monoxide emergency. If you smell gas, a CO alarm sounds, anyone feels unwell, or there is an unsafe flame, leave and call 0800 111 999 from outside.
Source and provenance
- Baxi 400 Combi 2.1 Installation & Service Manual · §11.2, printed p. 50 · 7875578-02
installation and service manual
Document 7875578-02
- Baxi 400 Combi 2.1 Quick Start Guide · printed p. 10 · 7876395-01
quick-start guide
Document 7876395-01
- Baxi How to repressurise your boiler with digital pressure gauge
homeowner guide
Checked 30/09/2026; the online page publishes no revision
Renting? Report it to your landlord or housing provider first. They are responsible for gas safety and boiler repairs, and the repair should not cost you.
Did this fix it?
After: Repressurise the boiler