Compact Size;Contemporary Design;4 Burner Modes (including off);Safety "Shut-Off" System;Programmable Weekly Timer with up to 30 Different On/Off Intervals;Power Failure Recovery (at least 30 Minute Backup for Time);Cool to the Touch Top and Side Panel Cabinet;Display Room Temperature, Set Temperature and Error Code;Automatic Ignitor Cleaning System;Only 2-3/4" Hole Needed in Wall for Flue Pipe;Wisper Quiet Operation;Easy Installation as Direct-Vent System requires No Chimney or Special Duct Work