Hi all, Firstly, really appreciate the forum, reading all the posts here I plucked up the courage to try my luck at my first custom loop! The issue I'm facing is, I've built the loop (it's a mess I know lol), there aren't any apparent leaks but the water isn't being pumped around the loop. I didn't think there would be an issue with 2x D5 res/pump combos? There are some long runs though as it's The Tower 900. I didn't think there was anything wrong with the waterblock or GPU blocks, all pressure tested as individual components before putting them in. Is my mistake not creating 2 separate loops here? 1. First EK D5 Res, outlet on the right goes straight into the CPU waterblock. But it doesn't even pump past this 2. Waterblock out (into first radiator in) 3. Into the EK 560 Radiator at the back 4. Radiator out (to the GPU now) 5. GPU in 6. GPU out 7. Into the 2nd EK 560 Radiator at the back 8. Radiator out, right down to the bottom where the splitter is, to both the drain valve and the 2nd res 9. Into the second res/d5 pump combo 10. Pipe that connects the 2 d5 res combos together Both reservoir's are filled to the brim but I can't open the lid of res, it would explode water out (probably gravity/levels?). I'm so confused now. When I turn it on, the res water levels do not drop as expected and nothing gets pumped around. I've checked and switched around molex's for the pumps. Any ideas? Many thanks in advance!