Dehumidifier degraded performance
My experience with dehumidifiers is that most usually last 2-3 years. I had 1 that lasted 7-8 years but that was a rare experience. I buy them at a store that has a cheap 3 year warranty. So far I have used the warranty 3 times on different units. It is a cheap way to extend the life of the unit. This works for me since the cost of repair is usually close to or exceeds the cost of the unit. As for normal cycles, mine is set for 40% and it runs until that humidity level is reached. There is never any ice build-up or should there be. Ice build-up occurs when the refrigerant charge is low, the filter is dirty,  or it is running in an area where the ambient temperature is below it's recommended temperature.