this model doesn't have a pump.Water is gravity fed in to the water bottle at the bottom left corner.there is a chamber at the back and to gain access you need to remove the lid and then undo the nut headed screws that hold the left side panel on (looking from the front).at the back left corner is a float switch in a chamber with a microswitch on the top that tells you the bottle is full.valves that push in to the water bottle can block up as well
ck, November 2010
