Arrived on site to perform fall tune up on a 2013 furnace located in attic client stated no issues and cycled heating mode on. Found filter dirty and in need of replacement. Found black flex and new ducting used and is okay at this time. blower assembly has slight dust and is okay. motor is good and amp drawls are in range. Inducer Motor is good and amp drawls are in range. All safety switches are operational. Evaporator coil is good. Heat exchanger has some heat impingement at this time. Drain lines have some debris and blew drain lines out and are good. Found voltage entering system was at 124 and rated at 120v. Recommend adding surge protectors to units to protect from high voltage and electrical surges that can damage or even short out system. Temperature rise is heating good at 47 degrees. Cycled system to ensure system operating. Went over all finding and areas of concerns with client. Went over repairs and recommendations with client. Client is aware of condition and how system