Morphy Richards oven display shows E3 and the oven does not heat or shuts down shortly after starting.

Safety first: Disconnect mains power. Allow the oven to cool completely before touching internal parts.

Steps to check:

• Check ventilation: Ensure the oven is installed with correct clearances and that cabinet vents and front louvers are not blocked.
• Inspect cooling fan operation: On models with a tangential cooling fan, the fan should run during and after cooking. Restore power briefly and start a low-temperature bake; if the fan does not run, switch off power and investigate the cooling fan motor and wiring.
• Locate thermal cut-out: The thermal cut-out (safety thermostat) is usually mounted on the top or rear of the oven cavity, often with two wires and a small round or rectangular body.
• Test continuity: With power off, disconnect the wires and test the thermostat with a multimeter. An open reading indicates it has tripped or failed.
• Manual reset (if applicable): Some thermal cut-outs have a small reset button. If present, press firmly until you feel a click, then re-test continuity.
• Replace if faulty: If the thermal cut-out will not reset or remains open, replace the cavity thermal cut-out thermostat. Also verify that the cooling fan and control board are not causing repeated overheating.

Note: If the oven repeatedly overheats and trips the cut-out, there may be a control board or sensor calibration issue that requires a technician.