While you wait for answers, we may have found some information which could help you.
Click here for Stopped Working ThermostatDimplex 403BT convector heater?
Dimplex duo heater?
Looking for reset button on dimplex convector heater DX25F10?
Faulty lights on Dimplex mk11?
Dimplex Cavendish Optimyst electric fire?
How to change LED driver on Dimplex fire?