How much does it cost to fix Ariston error code E 05?

Cost varies. Contact a Gas Safe registered engineer for a quote.

E 05 Low

Ariston E 05 Fault Code

Q: What does the Ariston E 05 fault code mean?

Your boiler is currently running its built-in frost protection mode to prevent internal parts from freezing, which usually happens during very cold weather.

Also written as E05 — same fault.

The Ariston E 05 fault code means: your boiler is currently running its built-in frost protection mode to prevent internal parts from freezing, which usually happens during very cold weather.. It appears on 2 Ariston models in our database.

Technical description: Anti freezing system, pump on

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 E 05 fault code

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

Euro Combi 30 MFFI
Euro Prisma 24

Source

Ariston E 05 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