Baxi · 400 Combi 2.1
E.00.21 boiler fault code
400 Combi 2.1
What E.00.21 means
The flue gas temperature sensor has short-circuited or measured a temperature above the range
Emergency guidance
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.
Open the emergency safety guideWhen to contact an engineer
Your boiler has shut down for safety. Don't keep resetting it. Leave it off and get a Gas Safe engineer to check it.
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.
Source and provenance
- Baxi 400 Combi 2.1 Install & Service Manual · §11.2 permanent faults table, p. 52
installation and service manual
Document 7875578-02