Error code
Baxi Boiler Fault Code 128
Quick answer
128
Flame detection has been lost during operation
First safe action
Check the boiler manual for any user-level checks allowed for this code.
Meaning
Baxi boiler fault code 128 usually means the boiler lit initially or tried to run, but then lost flame detection and shut down for safety.
Likely causes
- Intermittent gas supply issue
- Flame sensing fault
- Combustion or control issue
Safe first checks
- Check the boiler manual for any user-level checks allowed for this code.
- Try the standard reset once if permitted by the manufacturer.
- Stop using the boiler if the fault returns repeatedly.
How to reset
- Use only the standard user reset process if the manual allows it.
- Arrange professional diagnosis if the flame fault returns.
When to call an engineer
Repeated flame-loss faults should be assessed promptly by a Gas Safe registered engineer.
Safety warning
Do not attempt internal gas or combustion repairs. Persistent flame faults are not a DIY job.
Useful hub links
Related fault codes
118 for Baxi Boiler
System water pressure is too low
125 for Baxi Boiler
Water circulation or pump performance issue
130 for Baxi Boiler
Fan, flue, or air pressure sensing problem
133 for Baxi Boiler
The boiler has failed to ignite properly
117 for Baxi Boiler
System water pressure is too low
E1 for Baxi Boiler
A boiler sensor is giving an invalid reading
Relevant guides
Frequently asked questions
Can I keep resetting a Baxi boiler with 128?+
No. If 128 returns after one standard user reset, stop there and arrange a qualified engineer if the manual gives no safe next step.
Is 128 something I can repair myself?+
Boiler faults should be treated cautiously. Stay within the user checks in the manual, and leave gas, combustion, and internal boiler repairs to a qualified professional.