Changing fixed dump valve to flexible cable controlled valve

Yes there is a manual override in the form of an allen wrench that is used to engage the gear that opens the valve. I went with Drainmaster because it has metal gears and a better warranty than the other brands. I think that the people that may ever complain about failure of these dump valves (electric ones) don't maintain them and just run them until they fail. An occasional cleaning of the blades and lubrication with an all silicone lube will keep them humming for a long time.