I was given this as a gift from my husband.  My sister owned one and she said she loved it.  The first time I used it the unit overheated and damaged several pieces of jewelry. It took off the glaze on some of the gemstones, and some pieces of silver around the gemstones the silver became dark and lost it's shine. Some of the pieces did not get cleaned and polished enough so for those I put in the dipping solution I have used in the past and it cleaned them right up sparkling like new with the silver. I had used the setting at 480 twice in a row as this is what my sister uses in her machine.  I waited for it to heat up 5 minutes, then put jewelry with the cleaner they recommended. The solution  became was extremely hot to the point I could not take out the jewelry without gloves. The next day I put new solution in and set the settings at 480 two times, used a thermometer to measure the water temperature.  I did this 3 times with breaks in between and new solution each time. The temperature was reading 160 degrees.  My sister said her machine was not getting this hot and that she could easily put her hand in to take out jewelry. I an not sure I will be using this machine again, in the future I may try in without the heater on and see if it cleans with just the solution and timer set for 480.