Little green by bissel...hand wand will not squirt

SOURCE: I have a Bissel Proheat

Could have a bad pump, also there are solenoids, one of these could be bad.

SOURCE: bissell lift off pet-no suction through base (hose is fine)

I had a similar problem with mine. When you take the collector container out, if you reach your hand up, you will fill a round, plastic piece. Gently turn it and the piece pulls out. On the outside of the piece is a foam filter that may be plugged. There is another filter underneath the collection container in a pull-out drawer. Both filters can be washed with cool water, allowed to dry totally, then replaced. I understand that both of these filters need to be washed "frequently". It worked for me, hope it works for you.

SOURCE: BISSELL 1699 :WATER PUMPS THRU HOSE BUT NOT TO FLOOR NOZZLES

Did you blew thru the heater with both hoses off of it? If you did and it was clear, could be the pump, it is just working weakly. Is the top cover flush with the base in the back? If it has broken loose and has risen up, then it won't work. Here is a diagram that may help:

SOURCE: bad suction on bissell powerforce bagless vacuum

I took the bottom apart and it needed a new belt and that was the problem so it's fixed.

SOURCE: My Bissell Little Green won't

I also had the same problem as you.
Try suctioning up a full tank of hot tap water into the collection tank to soften/release a possible kink in the tubing inside of the vacuum hose that carries solution out to the spray tip.
I did this a couple of times and it worked. This info I found on the Bissell website.
Good Luck!