Question about solar panels

[matt4x4]

Here's the pic I drew up to help explain....
I'm having real issues trying to EDIT a post - this happened last night too (I just noticed) so don't go looking above since my edit didn't take and I'm not telling you anything new up there!
NOW, I'm going to tyell you what I tried to post last night!
The panels you have are like what I drew, TWO of the black rectangles in my dwg are ONE panel, so my drawing contains two panels total.

Water comes in the input, fills the big input/output pipe to the half way mark (Because it is physically blocked half way), water then starts to travel down HALF the WIDTH of the panel to the far end, the pipe at that end is NOT blocked and directs the water to the OTHER HALF of the panel and back to the OUTPUT half of that blocked pipe. (essentially makes the water travel in a U
If you end to end reverse a panel, you will just pump water in and right back out the big pipe since it does NOT have a PHYSICAL block in the pipe - the water never even makes it into the panel.
Flip your warm panels end to end, move the caps to the opposite end and reconnect in line where you just removed the caps.
An easy test is to remove one cap from the far end, stick a wooden dowel or some type of stick into the tube as far as you can, mark it and see how far in it went, if it went in half way your panel needs flipping end to end., if it went all the way in your panel is installed correctly.

[farmgirl]

Ok Matt: What you say makes sense...BUT....All 4 of my panels have stickers on them that tell which end is supposed to go where, and which sides are "inlet" and "outlet". We have them set up as per manufacturer's directions, so we are a bit confused. This is a REAL SORE subject between DH and me, but he says he will try and help me figure it out over the weekend. I will have him read your posts tonight, and perhaps he will try a different setup with the soalr. Thank you so much for the tips! At this point, i will try anything!

[farmgirl]

AHA! I went home on lunch hour to see if the panels would do anything different with a few adjustments. I read earlier that if your flow from your pump was too strong, you may get incomplete flow thru the panels. So, I diverted the water flow by half, and guess what........with the water diverted, and the pump on the HI setting, ALL the panels turned cool (ie, they were working!) Weird, but i still do not understand why the 2 center panels do not work if the pump is on low. Any ideas? I did not think this was so complicated!!!

[matt4x4]

Question:
Are you feeding the panels on the lowest point or the highest point?
It's probably best to feed at the lowest so any air pockets can get pushed out.
I would still take one endcap on each of the suspect panels off and see if you can push a stick/rod through to the other end cap - who knows, maybe the labels are applied wrong - unscrewing the caps is not much work so it may be worth a try.
Another thing is that trapped air may then escape and alleviate this issue in the future.