While you wait for answers, we may have found some information which could help you.
Click here for Replace Working Changingcannot turn off dimplex electric fire?
Dimplex Cavendish Optimyst electric fire?
Dimplex 403BT convector heater?
Looking for reset button on dimplex convector heater DX25F10?
Dimplex duo heater?
How to reset Dimplex storage heater CXL5N?