Performed a complete heating system maintenance and inspection. 2024 Gas system. Inspected and tested all electrical components and safety controls on the indoor unit; all components tested within manufacturer specifications. Spoke to client about duct cleaning. Verified system temperatures: return air temperature measured at 71°F; supply air temperature measured at 116°F and rising. Confirmed air filter was recently replaced by client; filter size is 20” x 25” x 4”. Aprilaire 210 client said he would change. I visually inspected the outdoor unit, The outdoor unit was in good condition Talked client about surge protection. Confirmed system was operating properly and heating upon departure. System Status: Operating normally at time of service.