Low output through SunHeater solar heater?

[Macboy]

I've set up my pool and solar heater through a diverter setup much like the photo here with the only difference being I have a ball valve on the run heading to the solar heater so I can cut it off completely and run only from the pump directly back to the pool bypassing the heater. When I shut off the solar loop and open the bypass I get "normal" output from the pump. When I shut the bypass and open the solar loop the output into the pool drops significantly. Less than half for sure.

Is this typical of these heaters? It would make sense that you'd want the water to take it's time through the solar but it's VERY noticeable and I don't want to over work the pump. Could I be harming the pump?

https://images.homedepot-static.com...ack-sunheater-pool-hardware-s240u-64_1000.jpg

 

[needsajet]

Nice to meet you via TFP

No you won't hurt the pump as long as water is flowing through it. Also I know it's not common sense, but the reality is that you want the flow through the panels to be as high as they'll handle. Did the panels include a recommended flow per panel?

If you add a bit more information, we can probably help more: Pump brand/model/HP, brand and square footage of solar heating panels, elevation difference from pool water level to the top and bottom of the panels.