Amathuluzi okulawula izinga lokushisa, azaziwa nangokuthi ama-valve we-thermostatic, kuyisicelo esijwayelekile sama-valve okulawula ukuhamba emkhakheni wokulawula izinga lokushisa. Iphuzu lawo eliyisisekelo ukuwulawula umthamo wokungena we-medium ye-heat (noma ye-cold) ku-heat exchangers, ama-air conditioning units, noma eminye imishini esebenzisa ukushisa noma ubanda ukuze kulawulwe izinga lokushisa lokuphuma kwemishini. Lapho umthwalo ushintsha, umthamo uyashintshwa ngokushintsha ukuvulwa kwe-valve ukuze kususwe imiphumela yokushintsha komthwalo futhi kubuyiselwe izinga lokushisa kwenani elibekiwe.