Just bought a 3000# unit with CAT pump and noticed that without the engine running and the house water on that there is a stream of water through the wand nozzle whether the trigger is pulled or not. When the wand is pressurized (engine running) it stops and remains stopped until the engine is stopped and the wand is depressurized then it flows again. I've had several pressure washers in the past and have never seen this before, a flow without the trigger being depressed. Is this normal with this unit? It's not much of a bother but I'm wondering if there is a defect in the wand.