Can you hear the pump running? Thermaltake is not exactly known for reliability when it comes to watercooling (not sure if Thermaltake uses Asetek pumps like 200% of all the other AIOs). You already mentioned a "odd noise", can you just get the fans off and just try starting the pump? Does it do anyhting? You can also unplug everything else for the test just so you can hear it more clearly.
The pump is in the block on the CPU
It might be the pump died and the water is just taking its time to heat up.
Thermaltake indeed uses Asetek.