Amathuluzi okulawula izinga lokushisa, azaziwa nangokuthi ama-valve e-thermostatic, kuyisicelo esijwayelekile sama-valve okulawula ukuhamba emkhakheni wokulawula izinga lokushisa. Isimiso sawo esiyisisekelo ukuhlela isivinini sokungena somphakathi opholile (noma oshisayo) ezikhumulweni zokushintshanisa ukushisa, kumayunithi wokushisa, noma kwezinye izinsiza ezisebenzisa ukushisa noma ukupholisa ukuze kulawulwe izinga lokushisa lokuphuma kwezinsiza. Uma umthwalo ushintsha, isivinini sokuhamba silungiswa ngokushintsha ukuvulwa kwe-valve ukuze kususwe imiphumela yokushintsha komthwalo futhi kubuyiselwe izinga lokushisa elibekwe.