** Is 220 Deg.F too hot for the operating temperature?? **
Yes... depending on where you're actually measuring it at. At the dryer exhaust outlet and on high, a high temperature of between 145°F and 155°F should be the most it should reach. It will usually cycle off until the temperature drops to 125°F or 135°F then heat up again.
There was a recent discussion on this very topic (although for a different brand of dryer). See if it sheds any light on possible causes (although the OP never did report back with the final result).