The Robertshaw 110 Series Water Heating Gas Valves are designed for universal replacement applications in water tanks. All models feature a built-in, non-cycling Energy Cut-Off (ECO) system to shut off all gas to the water heater in case of excessive water temperatures. The ECO is designed to detect over-temperature conditions and to open.
Jan 08, 2016 · Heater control valves can also leak from excessive corrosion from contact with old or contaminated engine coolant. Usually a leaking control valve will have to be replaced in order to repair the leak.