How much does it cost to fix Ideal error code H 3?

Typical repair cost for the Ideal H 3 fault is £120-220 including labour.

H 3 Medium

Ideal H 3 Fault Code

Q: What does the Ideal H 3 fault code mean?

Your boiler is struggling to accurately detect the temperature of your hot water, which means it may fail to provide a consistent supply or stop heating your water altogether.

Also written as H3 — same fault.

The Ideal H 3 fault code means: your boiler is struggling to accurately detect the temperature of your hot water, which means it may fail to provide a consistent supply or stop heating your water altogether.. It appears on 3 Ideal models in our database.

Technical description: ALTERNATING 'H' '3' GO TO FRAME 92

Typical repair cost £120-220 (including labour)

Engineer required

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

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Ideal models that show the H 3 fault code

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

Source

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

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