Mine does that if water is left inside it, so I turn mine upside down for 20 mins and then it works again, it don't happen when water has been left in over night, but if you do empty it out it should be fine, I've taken mine apart, and if water is left in it tends to leak a small amount into the batt compartment, I used pumber tape on all joints and the pump still does that, unless like I say you compleatly empty it out after each use, also the batt does tend to love being charged I think it self drains so keep it topped up with charge, well that seems to work for mine. Apart from that a brill lill machine for the price, I mounted mine on a small trolly.