How much does it cost to fix Ariston error code 3 0 4?

Typical repair cost for the Ariston 3 0 4 fault is £80-120 including labour.

3 0 4 Medium

Ariston 3 0 4 Fault Code

Q: What does the Ariston 3 0 4 fault code mean?

Your boiler has been manually reset too many times in a short period, so it has locked itself out to prevent potential damage.

Also written as 304 — same fault.

The Ariston 3 0 4 fault code means: your boiler has been manually reset too many times in a short period, so it has locked itself out to prevent potential damage.. It appears on 1 Ariston model in our database.

Technical description: Too much RESET

Typical repair cost £80-120 (including labour)

Engineer required

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

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Ariston models that show the 3 0 4 fault code

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

HS Premium Repair: £80-120

Source

Ariston 3 0 4 fault code information on this page is sourced and cross-checked against the official Ariston service / installation manuals for each affected model.

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