I had one of those units.
But the thing that really aggravated the crap out of me was the fact that the bags would come friggen loose!! After following everything to the letter, the bags would friggen lose their vacuum seal.
I'd go look in the freezer for a chicken, beef stew or a roast to cook and find out that the meat has come loose in the bag, is moving around, air has worked its way into the bags and there's no more vacuum seal, which is supposed to keep the air out of the bag!!
Over time, I found out that the appliance just wouldn't work!! It would vacuum, but the heater strip had stopped working!
I threw it out, along with all the bags that came with it, and got a Kenmore
vacuum sealer. It works great! No more losing the vacuum seal in the bags and no more loose bags caused by air getting into them and spoiling the food!!