I know this post is a few years old but I just had a similar problem with mine. A decorator had pulled the dryer out and in so doing dislodged the two pipes on the rear. He had put the pipes back on the wrong way round, so the pump was trying to send water up the drain. As the more rigid (clear) pipe is not a tight fit on the outlet nozzle, it was simply leaking out of the union - it would never have filled the tank in any case. Reversing the pipes (to the correct configuration) so that the black rubber one sends the water up to the top of the tank and the clear one drains any overflow down again from the bottom of the tank housing, solved the problem.
As an aside, I reckon one could rig up a permanent drain from the pump outlet and never have to empty the tank again!
Big Vern
July 2015