I wonder if I simply ended up with a defective unit? Within the first ten minutes of usage, mine stopped spinning, because one of the two nozzles no longer operated. What that meant was that all the water pressure (I was using a 2,350 PSI washer) came through one nozzle and I ended up with ugly gashes in my deck until I figured out what had happened and turned everything off.Following the instructions, I removed and cleaned both nozzles (that's a bit of a chore, by the way) although I did not see any obvious blockages. I also switched to a new pressure washer (rated at 2,000 PSI). Within a few minutes the same thing happened. I cleaned them again, only to have the same thing occur.I will say that Northern Tool was very good about things when I returned the unit.FWIW, I have used other surface cleaners with my pressure washer without any problems."