Air Heater jenis Tumbular di gunakan oleh PLTU Bukit Asam unit 3 yang memanfaatkan sumber panas flue gas dengan cara pemanasan awal. Dari data operasi dan data performance test dapat di kaji bahwa pemeliharaan pada kegiatan overhaul dengan variasi beban 60% dan 80% terhadap nilai efektivitas. Dari analisa dilakukan sebelum pemeliharan dengan beban 62% didapat nilai efektivitas sebesar 86,28% setelah selesai kegiatan overhaul nilai efektivitas menjadi 89,08%, sedangkan pada beban 85% sebelum pemeliharaan kegiatan overhaul didapat nilai efektivitas 86,41% setelah kegiatan overhaul menjadi 93,57%. Setelah dilakukanya pemeliharaan kegiatan overhaul dan pembersihan pada tube Air heater. Semakin tinggi efektivitas maka semakin bagus performa Air heater terhadap penambahan efisiensi thermal pembangkit.

Tumbular type air heater is used by Bukit Asam power plant unit 3 which utilizes the heat source of flue gas by means of initial heating. From the operation data and performance test data can be reviewed that maintenance on overhaul activities with a load variation of 60% and 80% on the effectiveness value. From the analysis conducted before the assessment with a load of 62% obtained an effectiveness value of 86.28% after completion of the overhaul activity the effectiveness value became 89.08%, while at the load of 85% before the maintenance of overhaul activities obtained an effectiveness value of 86.41% after overhaul activities to 93.57%. After the maintenance of overhaul and cleaning activities on the Tube Air heater. The higher the effectiveness, the better the performance of the air heater against the addition of thermal efficiency of the plant