Checked all operations in the heating mode for both systems and inspected the furnace filters. Checked all electrical components and preformed a combustion analysis for both systems. Both systems were burning fuel properly and all electrical components were within factory specifications. Today I found that both blower wheels had accumulated buildup on the blades which reduces airflow through the system. Talked with customer about the concerns and upon approval we cleaned both blower wheels. Both systems are operating properly at this time.