E430 Low

Baxi E430 Fault Code

The Baxi E430 fault code means: your boiler has detected a sudden drop or change in water pressure and has temporarily paused to re-check the system levels.. It appears on 23 Baxi models in our database.

Monitor it

This is a minor fault. Keep an eye on it and mention it at your next annual boiler service. Reset the boiler and see if it clears.

Technical description: Water pressure temporary test.

What causes the Baxi E430 fault?

This fault occurs when the boiler's internal sensor detects an abrupt fluctuation or drop in water pressure while the system is running. The most common reason is air trapped in the radiators or a small leak in the system pipework that has caused the pressure to fall below the required operating level.

This fault is more common in autumn when homeowners turn their heating back on for the first time, as air pockets and old leaks often reveal themselves after the system has been sitting idle.

Typical repair cost £0-120 (including labour)

DIY fix possible

Check the pressure gauge on the front of the boilerIf the pressure is below 1 bar, use the filling loop handles underneath the boiler to top it up to 1.5 barTurn the boiler off and back on at the power switch to reset the fault

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Baxi models that show the E430 fault code

Click a model for the full fault code list and model-specific repair notes.

Source

Baxi E430 fault code information on this page is sourced and cross-checked against the official Baxi service / installation manuals for each affected model.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 27 April 2026