I have had two of these pressure washers and both developed the same problem: After a year or so of normal household type service the units develop a reluctance to develop high pressure when the trigger is pressed on the wand. The problem is sensitive to the nozzle used, with the higher pressure nozzles developing the problem first and as time passes the high pressure simply will not actuate. The first unit I could force the high pressure to actuate by first removing the nozzle, actuating the trigger for a few seconds then putting the nozzle back in. Generally it would continue to supply high pressure only after the first press of the trigger, then the procedure would need repeating. The second unit simply does not develop high pressure on any of the nozzles.