my nilfisk pressure washer (p 150.1-10) starts to pump before i use the trigger on the lance.there are no leaks on any part of the machine and when i use the trigger it is not pumping at full pressure.do you think it could be the pressure switch(part no al127500010)? i am a service engineer ,but not on this type of equipment.

DAVID LEWIS, March 2012

Had similar on my karcher, seem to remember something about the inlet hose, I think I disconnected the outlet, m/c unplugged to let water flow through, think possible air lock. As I had just got it back after lending it out, I thought the worst, as you do. But No just something simple like that.

SD, March 2012