Error code
Baxi Boiler Fault Code 133
Quick answer
133
The boiler has failed to ignite properly
First safe action
Check whether other gas appliances appear to have lost supply, without dismantling the boiler.
Meaning
Baxi boiler fault code 133 usually means the boiler could not ignite or complete its startup sequence correctly.
Likely causes
- Temporary gas supply interruption
- Ignition or electrode fault
- Control problem affecting startup
Safe first checks
- Check whether other gas appliances appear to have lost supply, without dismantling the boiler.
- If the manufacturer permits a user reset, try the standard reset process once.
- Stop further reset attempts if the fault returns.
How to reset
- Follow the reset instructions shown on the boiler control panel or in the manual.
- If the code reappears after one reset, book a qualified engineer.
When to call an engineer
If the fault returns after one reset, stop there and arrange a Gas Safe registered engineer.
Safety warning
Do not remove the boiler casing or try to work on gas, ignition, or combustion components yourself.
Useful hub links
Related fault codes
125 for Baxi Boiler
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E20 for Baxi Boiler
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Relevant guides
Frequently asked questions
Can I keep resetting a Baxi boiler with 133?+
No. If 133 returns after one standard user reset, stop there and arrange a qualified engineer if the manual gives no safe next step.
Is 133 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.