I-heater yepayipi iwumshini wokonga amandla oshisa kuqala indawo yokushisa. Ifakwe ngaphambi kokushisa okuphakathi kokushisa ukushisa ngokuqondile okuphakathi, ukuze ikwazi ukujikeleza ukushisa emazingeni okushisa aphezulu, futhi ekugcineni ifinyelele inhloso yokonga amandla. Isetshenziswa kakhulu ekushiseni kwangaphambili kwamafutha kaphethiloli njengamafutha anzima, i-asphalt, namafutha acacile.