How much does it cost to fix Ariston error code EE 3300?

Typical repair cost for the Ariston EE 3300 fault is £120-200 including labour.

EE 3300 Low

Ariston EE 3300 Fault Code

Q: What does the Ariston EE 3300 fault code mean?

Your boiler is struggling to detect the temperature outside, which may cause it to run less efficiently than usual.

Also written as EE3300 — same fault.

The Ariston EE 3300 fault code means: your boiler is struggling to detect the temperature outside, which may cause it to run less efficiently than usual.. It appears on 4 Ariston models in our database.

Technical description: Outdoor sensor open circuit

Typical repair cost £120-200 (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 EE 3300 fault code

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

Challenger 80E Repair: £120-200
E-Combi One Repair: £120-200
E-Combi One 30 Repair: £120-200
Microsystem 15 Repair: £120-200

Source

Ariston EE 3300 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