Skip to main content
OVERHEAT FAULT CODE
Myson

High Temperature Lockout

High Severity Engineer Required

The boiler exceeded its safe operating temperature and the overheat thermostat has tripped.

Step-by-Step Fix Guide

  1. Step 1

    Allow the boiler to cool

  2. Step 2

    Check the system has adequate water

  3. Step 3 Engineer only

    A Gas Safe engineer should check the pump and system circulation

Gas Safe Reminder

Work on gas appliances must be carried out by a Gas Safe registered engineer. The steps above cover safe checks a homeowner can perform - any internal component replacement requires a qualified professional. If in doubt, always call an engineer.

Are you a Gas Safe Engineer?

Access technical fault data, wiring diagrams, and parts lists. Free for verified Gas Safe engineers.