Hotpoint Ultima FFA97G motor not cutting out

Hi, This is an odd problem. It’s a Frost Free Hotpoint Ultima FFA97G. The freezer temperature display says 23 degrees so the motor is not cutting out but a thermometer in the freezer says it’s less than -20 degrees.

I am concerned that the motor will burn out.

Two days ago there was a puddle of water and ice in the base of the freezer. I took the cover off the workings inside and cleared the drain hole (it was iced up), removed all ice, dried it and put back together. When I switched on again it rapidly reduced temperature but stuck at -12 deg and the motor continued running. A thermometer said the temp was around -18 deg. Yesterday I switched off for half hour, switched back on, the motor ran with small pauses in between. The temp said +23 deg but it wasn’t – it was below -20.

I don’t know what to do next or even if there is something I could do personally. Could anyone please advise? Thanks in advance for any suggestions.