Performed 1 system heating maintenance. System has no surge protection just a pass through electrical switch. Recommend installing surge protector to keep electrical components from damage. Blower wheel very dirty and Needs to be chemically cleaned. System operating properly at this time. Chemically cleaned blower wheel. Blower wheel is in brand new condition. Installed surge protector. System is now protected electrically. Homeowner wants paper copy of invoice sent to her.