Heating maintenance and safety inspection. Cleaned and serviced two furnaces for a VIP service plan member. Tested all mechanical components. Cleaned all sensors. Tested both gas valve voltage and inlet/outlet pressures. Tested both the inducer and blower motor amperages. Found in both furnaces, the ignitor and flame sensor were very corroded. The customer agreed. Furnace filters were just changed. Heating Systems are cleaned and operating properly at this time. Giving customer estimates for a new energy-efficient water heater due to age and intermittent issues.