A7dh65b2a i have a 65 pint dehumidifier for two years and it's starting to give us problems. it does frost up but i just turn it a few days and it's fine. the problem is that it wont't shut off, i have to unplug it. and the fan speed only runs on high, you can press the fan speed switch but nothing happens. any suggestions?

The thermistor is bad. Believe me - I know this too well. Bought 2 of these and both died w/ this same issue right after 1 yr warranty expired. The thermistor is located on bottom-right side of evaporator coil. It has a chrome metal clip that holds it against the evap coil copper tubing. It also has a 2-wire harness that runs out of it up to the front-panel control board. Beware that if you had a big ice-up like this, there is potential damage to the power control board too. It will get a puddle of water under it when the ice thaws and this will cause the circuit board to corrode. Your power control board probably has corroded due to condensation from the extended freeze-ups. If you're lucky, you might be able to clean off the corrosion and it may still work. To fix the freeze-ups, you can order another front panel control board (the one w/ all the LEDs/controls/7-segment displays on it). It comes w/ all the sensors (including the thermistor). It was ~$38 when I purchased it at RepairClinic.com (twice...).

Normal operation, the unit has sensed icing and is in the defrost mode (compressor off and fan on high). When the ice melts normal operation will resume.