Abstract: A hot water shut off valve for use for domestic household water shower use which shuts off excessively hot water. The valve generally includes an water inlet source opening to an inner chamber. The inner chamber has an outlet source at the base of said chamber, a sealing means communicating with said outlet sources for alternately turning on or off the flow of water from said inlet sources through said outlet sources. The sealing means is urged against the base of said mixing chamber by means of a paraffin power element communicating with a spring. In the preferred embodiment, a reset member is provided to reset the flow of warm water from the inlet source to the outlet source.