I got a false bottom for Christmas. I tried it out with just water and had no flow. My false bottom has a barb an my valve has a barb and I use some vinyl tubing to connect the two. I did some experimenting. I disconnected the tubin from the valve and I had good flow. Added the tubing to the valve and had good flow. Connected the false bottom to the tubing and no flow. However it did have decent flow when I sucked the tubing on the outside of the tun to get some flow started
What vessel are you using and how much water?
Did you have any tubing on the outside of the valve? You may need to have the outside tubing flowing into a lower bucket to get the right amount of siphon effect. Give that a try.
I have a 10 gallon Igloo cooler. So try longer tubing? A friend of mine suggested trying bigger tubing on the outlet too.
I assume that you have a SS false bottom, similar to the one pictured below.
The bottom of your igloo cooler is slightly domed causing the space between the cooler bottom and the bottom of the nut on your false bottom to be very small. There are 2 remedies to your problem. Grind the nut on the bottom of the false bottom thinner, or cut slots in it to allow more room for the wort to flow through. Or bend the false bottom slightly increasing the concave shape of the false bottom.
[attachment=0]12 Inch Stainless Steel Flase Bottom.jpg[/attachment]
