I finally decided to get off my arse and give watercooling a go so I went off to Specialtech and bought myself the 'Thermaltake VD4000BWS Kandalf LCS': link.
Being a watercooling noob with a 4 year old case that was getting too small for my components I decided it was probably best to buy an in-built system.
I followed the manual step for step, built the loop (Pump -> CPU Block -> Radiator Door -> Reservoir -> Pump) as short as possible and made sure the barbs were all as tight as possible to make sure there were no leaks.
Being my first time I decided it was probably best to do it with no equipment in.
Following the manual I filled the res with water, turned on the pump and kept on filling as the water level decreased. I put one entire bottle (500ml) of the provided coolant in the system which filled the res to max. I realised there were bubbles in the system that weren't moving and there seems to be no flow coming from the radiator to the res, the tube is clearly see through. When the pump is turned off the water flows back through the system and you can see it rising up the tube from the res. My only possible suggestion would be a blockage but being new I have no idea.
Does anyone know what the problem could be?