Try and post some pictures of your plumbing system.
First make sure your strainer basket housing winterizing plug is not leaking air and that your strainer lid gasket is good. Put the multiport valve in the recirculate position then close the skimmer and the main drain valves. Remove the pump strainer lid and fill to the top with water. Put the lid back on then start the pump and open one of the skimmer valves just a little until the water stops comming from the inlet pipe then shut the valve and turn the pump off. Then open the pump strainer lid and fill with water again. Keep this cycle up until you get a good flow thru the one skimmer. Once you establish a good flow thru this one skimmer then slowly open the other skimmer (or main drain) until the pump starts to unprime then quickly shut the skimmer (main drain) but keep open the one skimmer with good flow. After you establish good flow again then open the other skimmer valve (main drain) again unit it starts to unprime then shut this valve again. Keep doing this until you have good flow thru all your skimmer and main drain valves. Every time you shut the pump off make sure you close all your inlet valves. You also may want to put a check valve on the discharge side of your pump. Hope this helps.
Thanks for all the great advice! We followed imfignewton's advice with stopping and starting and were finally able to get it going! I've attached a photo of the plumbing. All our plumbing is on a deck that will be enclosed by a shed when we get around to building it. ;-) With all the valves open, it's quite a lot of vertical pipe. After getting the one line going, we got the others one by one.
We'd need a lot of check valves if we put one on each vertical run. We currently just have one check valve installed after the filter. Shouldn't the water stay in the pipes now that we have it started? I'm hoping this hassle will only be when we open the pool each year...
On another note, our brand new DE filter is a Pentair FNS Plus 36. In the manual it said when you get it running the first time time to mark the pressure so you know when to backwash. Well, now that the pool is started, the guage still reads 0. I can call Pentair on Monday, but maybe someone here will know what's going on! (I posted this question on the equipment discussion board.)
Nice picture. you did all that yourself? I think you are getting zero pressure because you still have the multport set to recirculate. First, turn the filter off, never change the multiport setting with the filter on. Then set it to filter. You will have to bleed the air out of the filter with the valve under the gauge. Leave it open until water comes out, and don't stand in front of the opening, unless you have your bathing suit on.
I can take very little credit for the plumbing myself. My job was to put the purple PVC primer on the pieces. My husband did the rest!
We just got a replacement gauge from Pentair today and now the filter is showing pressure. We must have just gotten a bum gauge.
PS: We put a clear flexible plastic tube on the pressure release so that we wouldn't spay ourselves and the inside of our future shed. It channels the air and water under the deck. :-)