The H2C is in my opinion an accident waiting to happen. 1: its pressurised. 2: it can't be refilled or serviced 3: its built to fail just outside the warrantee. 4: I now know its performance was poor compared to average water cooled units.
I have 2 XPS730H2C's my son has one and I the other. when his system registered a pump failure it would not boot but just shut down. turning the computer on its side allowed it to boot and the pump failure went away. so I resolved to fix the system myself. I swapped him my cooler and worked on his.
1: remove h2c cooler (you will need a very long crosshead screwdriver. clean tim off with isopropanol. push down on center of valve located on tec plate. push until you relieve the pressure inside (do this outside your home!)
2: install a reservoir before the pump (I used an innovatek one with 3/8" ID - 1/2"OD tubing and fittings) cut rubber pipe carefully with sharp craft knife then remove old tubing. don't damage the fittings themselves or it will leak!
3: remove tubing from inlet to chipset block and remove inline strainer from inlet.
4: Remove base plate from CPU block (4 screws) and carefully, with a sharp object prise out the plastic insert which so some unknown reason is there in the first place!. don't damage the outer seal "o"ring and replace the base plate (observe orientation- notch in plate)
5: put H2C back in and refill. it is advisable to try and blow through the whole assembly prior to installing it just to see if there are any more restrictions.
You will need at least 3m of tubing, the clamps on the h2c can be reused with the new tubing. some anti kink coiling is a good idea to stop and pinching of the tubing. a very deep reservoir is needed as when the system is very hot or tweaked (nvidia esa) the pump runs even quicker causing turbulence in the reservoir pushing air into the system. i have taken all the Nvidia performance/ntune/system monitor off of my system because it causes constant crashing (not just since I fixed the cooler)
As far as I know I am the only person to ever fix this cooling system. I have looked everywhere. There is a youtube video series of someone supposedly fixing one but it was not successful as he didn't know about the cpu block restriction or filter. also he was an idiot and made assumptions about the technology without any real experience. another upgrade that should be done is to remove the foil layer from on top of the chipset plate and scrape off the glue with a blunt knife. this will lead to a problem where the cooler will no longer make contact properly with the chipset. I fixed this by bending off one of the fins from the TEC cooler and trimming it down until it would fit in top with a pair of tin snips. tim underneath, tim on top & tim the cooling block (sandwich the piece of tin)
My system never gets hotter than 45c degrees under full load. BF3
Here is a picture of the system running (not pretty but I will get around to that later).