The Core i5 7500 can be cooled with a normal fan without issues. Using a 240mm AIO should give you really awesome load temps.
This is probably either a pump problem/malfunction/not working at all, cables plugged in the wrong motherboard conector, and/or cables not connected at all, etc.
Sometimes people forget to remove the protective sticker from the pump copper plate.
Other times they forget to connect the SATA cable.
Check this installation guide:
View: https://www.youtube.com/watch?v=zGi-hTkRy00
You should really take a closed look to all your cables conections, then when you are 100% sure all the cabels are right, put your hand over the pump and try to feel if its working.