Iheater yokucwiliswa isetshenziselwa ukushisisa uketshezi, uwoyela, noma olunye uketshezi lwe-viscous ngokuqondile.Izifudumezi zokucwilisa zifakwa ethangini eliphethe uketshezi.Njengoba i-heater ithintana ngqo noketshezi, iyindlela ephumelelayo yokushisisa uketshezi.Izifudumezi zokucwiliswa zingafakwa ngezinketho ezihlukahlukene ku-tank yokushisa.