XPS 720 H2C - diagnostics for water cooler unit?

Hello,

RE: Overheating CPU on XPS 720 H2C

Over the last few months, my CPU fan has been getting progressively louder.

The beast has always been noisy, so I don't overclock it anymore.

I clean the grills etc regularly, and just pulled out the H2C unit and gave the whole inside of the PC a thorough dust before applying thermal compound to the CPU and re-assembling.

My CPU temps idle around 50-55C, but playing StarCraft II or World of Warcraft drives them up to 80C with the CPU fan at 2400rpm or more (loud!).

I was wondering if there was any diagnostics or tests I can do to see if the H2C unit is functioning properly (if at all)?

If the water cooling wasn't working at all, would this explain the symptoms? or would the PC blow up!?

Any relevent advice appreciated ('relevent' to prevent don't run with scissors :)

Cheers,

Il.