Owokuqala uwukuphakela amanzi, okungukuthi, ukufaka amanzi kubhayela. Ngokuvamile, ifakwe ipompo ekhethekile ukwenza inqubo yokuphambukisa amanzi ibe lula futhi isheshe. Lapho amanzi ethulwa ku-boiler, ngoba abamba ukushisa okukhishwe ukushiswa kwamafutha, umusi ngokucindezela okuthile, izinga lokushisa nokuhlanzeka kubonakala. Ngokuvamile, ukwengeza amanzi ku-boiler kumele kudlule izinyathelo ezintathu zokushisa, okungukuthi: ukunikezwa kwamanzi kuyashiswa ukuze kube amanzi agcwele; amanzi agcwele ayashiswa futhi ahwamuke ukuze abe isitimu esigcwele; isixhumanisi.
Ngokuvamile, amanzi kubhayela wesigubhu kufanele kuqala ashiswe ku-economizer ekushiseni okuthile, bese ethunyelwa esigubhini ukuze axubane namanzi abhayela, bese kungena umjikelezo wokujikeleza nge-downcomer, futhi amanzi ashiselwe esikhuphukeni Ingxube yamanzi e-steam ikhiqizwa lapho ifinyelela izinga lokushisa lokugcwala futhi ingxenye yawo iyahwamuka; khona-ke, kuye ngomehluko wokuminyana phakathi kwesikhuphukeli nesiphansi noma iphampu yokujikeleza ephoqelelwe, ingxube yamanzi esitimu ikhuphukela esigubhu.
Isigubhu siwumkhumbi we-cylindrical pressure othola amanzi esishibhini samalahle, ohlinzeka ngamanzi ku-circulation loop futhi ulethe isitimu esigcwele endaweni yokushisa ephezulu, ngakho futhi siyisixhumanisi phakathi kwezinqubo ezintathu zokushisisa kwamanzi, ukuhwamuka kanye nokushisa okuphezulu. Ngemva kokuba ingxube yamanzi esitimu isihlukanisiwe esigubhu, amanzi angena emgudwini wokujikeleza nge-downcomer, kuyilapho isitimu esigcwele singena esimisweni sokushisa kakhulu futhi sishiswa sibe isitimu ngezinga elithile lokushisa okukhulu.