How can I fix my BISSELL Proheat Clearview 1699?

Sure, it's possible, but not likely if you have water coming out of the attachments. That alone tells us the pump is working. All water is mixed with solution and goes through the heater, there is a 'T' fitting that splits the flow from spray nozzles to attachments. Most likely the spray nozzles are plugged with dried soap from the solution. You are supposed to turn the solution switch to water only and run it for a while every time you use the machine to flush the lines and avoid plugging the nozzles. Nobody does, though.
But to answer your question, there are 3 hoses connected to the pump. The one on the left (looking at it from the front of the cleaner) comes from the solution flow selector switch, that's the input line. The hose on top of the pump goes to the left side of the motor housing, a sort of vacuum shut off valve so water flows only if motor in running, and the fitting on the right goes to the rest of the system, that's the output line of the pump. You can easily see where the flow stops by removing a hose farther down the line from the pump, eg. pull the hose off one of the nozzles, if water flows out of the hose, the nozzle is the blockage. Just works your way through until you find where the water flow stops.

CA
May 2012