Same tank but 2 pumps, you can remove the pump really easy (just pull them out) and check the screen for clogs. If you use a lot of that blue fluid it has a tendency to leave this gook in the filter screen and prevents the water from getting to the pump. If there is no clogs switch the 2 pumps and see if the back works and not the front, then you know you have a defective pump. About 25 bucks will solve that.