I have a commercial stack by Speed Queen. The only number etched on the unit is GH22052091, which is on the upper rear edge of the dryer. I have looked everywhere inside & out, up & down and this is the only number but I can find no reference to it. Besides parts I need for the dryer like the belt and 2 roller wheels the washer when put in spin only cycle or goes to spin in the wash cycle will drain then start to spin then stop for the remainder of the spin cycle leaving the articles soaking and need to be hand wrung. The pump runs as it does drain. Is this a sensor or an electric problem? How would I trouble shoot this? Also could the Model Number be discontinued? Thank You very much in advance for any help in these matters.