How much does it cost to fix Vaillant error code P.04?

Typical repair cost for the Vaillant P.04 fault is £100-200 including labour.

P.04 Medium

Vaillant P.04 Fault Code

Q: What does the Vaillant P.04 fault code mean?

Your boiler has entered a configuration mode that resets its internal central heating settings back to their original factory defaults.

Also written as P04 — same fault.

The Vaillant P.04 fault code means: your boiler has entered a configuration mode that resets its internal central heating settings back to their original factory defaults.. It appears on 1 Vaillant model in our database.

Technical description: Reset eGas CH (Central Heating) check programme: Calling up the programme deletes all of the CH corr

Typical repair cost £100-200 (including labour)

Engineer required

This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

Find a Gas Safe engineer

Search the official register for a qualified engineer in your area.

Gas Safe Register →

Vaillant models that show the P.04 fault code

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

ecoTEC exclusive Repair: £100-200

Source

Vaillant P.04 fault code information on this page is sourced and cross-checked against the official Vaillant service / installation manuals for each affected model.

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