the h2o sensor may not be the only problem, some thing else is setting off the sensor, a pin hole in the hose, a loose connection, cracked lines, plug lines, blockage of sensor that controls the h2o unit, look at the whole picture, housing, gasket is that area, too much h2o, not enough h2o, gases mixtures + h20's, make sure you have the air pressures sucking and pushing through the line.
you are going to have to a service manual and general information how the h20 system works in that vehicle. test points.
www.ask.com/year/mfg.name/make/model/how/does/H20/system/works/on/vehicle/