The Robertshaw 710-205 is a compact, natural gas snap-action hydraulic gas valve designed for residential gas appliances like furnaces and water heaters. It uses a pressure-sensitive mechanism to regulate the flow of gas based on signals from a thermostat. When the thermostat detects a need for heat, it sends a signal to the valve, which opens and allows gas to flow to the burner. ... https://www.partshnc.com/710-205-robertshaw-12-ngsnapactvlv36-5890f