Checked all operations in the heating mode and inspected the furnace filter. Checked static pressure and found that the system has high static pressure. The customer and I went around the house to make sure all the vents were open and I put in a new filter and retested the static pressure and it passed. Checked all electrical components and preformed an combustion analysis. Look at the blower wheel as well it didn’t have a lot of buildup or dirt on it. All electrical components were operating properly and the furnace was burning fuel properly as well.checked heat exchanger and there was no cracks or rust. Furnace is operating properly.