How much does it cost to fix Myson error code 10.4?

Typical repair cost for the Myson 10.4 fault is £100-£250 including labour.

10.4 High

Myson 10.4 Fault Code

Q: What does the Myson 10.4 fault code mean?

Your boiler has switched itself off to prevent overheating, likely because the internal temperature has become too high.

Also written as 104 — same fault.

The Myson 10.4 fault code means: your boiler has switched itself off to prevent overheating, likely because the internal temperature has become too high.. It appears on 2 Myson models in our database.

Technical description: Boiler shut down by limit thermostat

Typical repair cost £100-£250 (including labour)

DIY fix possible

Turn off the power supply to the boiler and let it cool down for at least 30 minutes.Check that all your radiator valves are open and not turned off.Press the manual reset button, which is usually found behind the front panel or at the bottom of the unit.

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Myson models that show the 10.4 fault code

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

Source

Myson 10.4 fault code information on this page is sourced and cross-checked against the official Myson service / installation manuals for each affected model.

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