Please re read before you post.... I found it difficult to read, almost quit three times....

- Did you bleed the system by running the internal pump to air out the system?
- Yes, the bottom pipe will be cold for a good long time
- Can you post the image or images of the hose you found loose?
- The over flow container will be failing soon. Watch for discoloration. Once the container starts looking it's black color (and goes a bit brown), change it.

Good Luck Mate.