BoilerFaultCodes 8
shut down on a controlled stop
Baxi Avanta Plus 30s system Fault codes & diagnostics
22 fault codes with plain-English explanations, severity ratings, DIY guidance, and repair cost estimates.
System Gas 2008 onwards Discontinued
GC Number 41-288-12
Download the Baxi Avanta Plus 30s system manual
PDF
Versions & GC numbers
The fault code is already on your display
Note it down before pressing reset — resetting clears the code immediately. How to read fault codes →
Severity at a glance
Each cell = one fault code. Hover to identify. 22 Unrated
Which version do you have?
The GC number on your boiler's data badge identifies the exact appliance and production years, as recorded in the UK Product Characteristics Database.
| GC number | Appliance (register name) | Produced |
|---|---|---|
| 41-288-12 | Avanta Plus 30s system | 2008–2015 |
Appliance names and production years are taken from the UK Product Characteristics Database (the SAP/SEDBUK register). Where a GC number is also printed in this model's own manufacturer manual, both sources were checked to agree.
Just want the most common Baxi Avanta Plus 30s system faults?
The top 6 problems in plain English — with causes, DIY checks and repair costs.
Fault codes
All 22 documented codes
Tap any card for details
9
External interlock circuit open; boiler shut down
d5
Control stop from 3 till 10 minutes; set flow temperature (t1) has been reached and the heating demand still exists.
d8
Control stop; measured flow temperature (t1) is higher than the flow temperature set (Tset flow).
d9
Shut down; maximum temperature rise is exceeded, dT between supply and return temperature ≥ 45°C, rate of rise in flow temperature > 1°C/sec, or boiler-start with no through flow.
é0
Flow or return sensor fault. Short circuit in the flow, return or boiler temperature sensor. Defective or not (properly) connected flow, return or boiler temperature sensor.
E01
high limit temperature protection device switches off the boiler in a lock out mode
é1
Error
é2
Error
é3
Control unit or earth fault. Mains supply not correctly earthed. Control unit faulty.
Showing 11–20 of 22
é4
More than 5 start attempts without any flame formation.
é5
No ionisation or ionisation failure more than 5 times during one heat demand.
é6
Unwanted flame formation
é7
Error
é8
Fan fault
é10
Error
é11
Air box temperature to high
é13
Error
é43
Parameter limits
é44
Parameter check
Showing 21–22 of 22
é45
Default parameters
OT ERROR
Display flashes when a frost thermostat connected in parallel to the Celcia 20 calls for heat