How much does it cost to fix Baxi error code H.02 – .04?

Typical repair cost for the Baxi H.02 – .04 fault is £90-280 including labour.

H.02 – .04 High

Baxi H.02 – .04 Fault Code

Q: What does the Baxi H.02 – .04 fault code mean?

Your boiler's computer brain is momentarily confused by some internal settings and cannot operate correctly.

Also written as H0204 — same fault.

The Baxi H.02 – .04 fault code means: your boiler's computer brain is momentarily confused by some internal settings and cannot operate correctly.. It appears on 24 Baxi models in our database.

Technical description: Temporary error- parameter fault. Incorrect parameters.

What causes the Baxi H.02 – .04 fault?

This fault occurs when the boiler's main control board loses its specific configuration settings or detects a mismatch in its internal programming memory. It is often triggered by a sudden electrical surge, a failing memory chip, or a breakdown in the communication between the boiler's internal components. Because the boiler no longer knows its own operating limits or model type, it shuts down as a safety precaution.

Typical repair cost £90-280 (including labour)

DIY fix possible

Locate the selector knob on the front of the boiler control panel.Turn the knob to the 'Reset' position and hold it for five seconds.Return the knob to your desired setting and wait for the boiler to restart.

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Baxi models that show the H.02 – .04 fault code

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

Source

Baxi H.02 – .04 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