A pressure actuated water shutoff valve is presented. The shutoff valve comprises an upper housing and a lower housing where the upper housing is coupled to the lower housing. The lower housing has a water inlet and a water outlet with a flow passage therebetween. The lower housing includes a plunger seat configured to receive a shutoff plunger. The upper housing includes an chamber having a piston bore in which reciprocates an piston, coupled to the shutoff plunger. In response to a first pressure condition, the piston lifts the shutoff plunger off its seat allowing water to flow through the lower housing. In response to a second pressure condition, a biasing spring seals the plunger against its seat, shutting off water flow through the valve.