I have a Kenmore 253-260721000 that is setting off an alarm with a readout of d zero temp. When the problem started it read CE and temp and it was suggested we replace the electronic control board with the result the CE disappeared but the d with the temp replaced it and the alarm sounded. We have checked the door alignment, coils, etc. The temperature is staying at about -10 F and seems to be running fine except we cannot stop the alarm except by manually cancelling every 12 hours.. A repair company was called and they said the door had to be replaced for about $400 for parts and labor. We just want to stop the alarm from sounding since everything else appears to be running okay. Any suggestions?

Try cleaning the coils under the unit with spray soap and water. Unplug and remove the back, then spray down the coils with soap and wash off with hose nozzle and vacuum up with wet-vac. After that let me know how it works. The alarm is due to it overheating. It will ruin the compressor to leave it dirty.