Baxi Boiler E133 Error Code

Gas supply interrupted or flame failed to establish on Baxi boilers.

E133

Moderate DIY

The boiler tried to light, didn't detect a flame, and locked out. Baxi's reset guide names three culprits: the gas supply, the ignition or flame, and a blocked condensate pipe. In a cold snap the condensate pipe is the one to check first, since Baxi links E133 to a frozen pipe.

Compatible models

Described in the Platinum Combi and Combi 825 user manuals and in Baxi's own reset guide; the number 133 also appears in the error tables of the Baxi 124 and Duo-tec 2 Combi GA user manuals.

Also shown as

The Platinum Combi shows it as E1 alternating with 33 and describes it as a gas supply interruption, failed ignition or undetected flame. E128 (flame failure) is a close relative.

Difficulty

Start with the safe checks below; a worn part may need replacing.

How to fix
When to call a pro
Parts
FAQ

Not sure you are reading the code right? See how to read Baxi boiler codes.

Safety first: never take the casing off a gas boiler. If you smell gas, open windows, don't use light switches, turn the gas off at the meter if you can and call your gas emergency number from outside. A carbon monoxide alarm going off means the same: switch the boiler off, get fresh air and call.

How to fix Baxi E133

Test another gas appliance
Turn on a gas hob or fire. If nothing lights, the problem is with the supply: check that a prepayment meter has credit and that the gas hasn't been turned off, and contact your gas supplier if it has gone off for no reason.
Thaw the condensate pipe if it's freezing outside
Switch the boiler off at its controls and at the wall first. Follow the plastic condensate pipe from the boiler to where it runs outside; ice usually forms on the most exposed stretch. Warm it with a hot water bottle, a microwaveable heat pack or warm water from a watering can (never boiling water from the kettle), then switch the power back on.
Reset once
Press the reset button, or turn the selector to R and hold it there for at least 5 seconds. The temperature should replace the code, and if there's a call for heat the burner light should come on within a few seconds.

When to call a technician

Gas on at the hob, condensate clear, and E133 is back after a reset: the ignition side needs a Gas Safe engineer. Baxi says frequent lockouts point to a fault, even if each reset seems to work.

Parts linked to E133

These are the parts an engineer usually checks for this code. They sit inside the sealed casing, so leave them to a Gas Safe registered engineer.

Frequently asked questions

Which Baxi models show the E133 code?

Described in the Platinum Combi and Combi 825 user manuals and in Baxi's own reset guide; the number 133 also appears in the error tables of the Baxi 124 and Duo-tec 2 Combi GA user manuals.

Can I fix Baxi E133 myself?

Only the outside checks above. If they don't clear E133, the fix is inside the boiler and needs a Gas Safe registered engineer.

Other Baxi boiler codes

Last reviewed 2026-10-21. Codes and steps can vary by model; check your owner's manual.

Sources we checked