Coolent Problem

Thought id give our 2.0LTR TDCI a coolant change the other day, so I removed the pipe on the right hand side of the rad (removed light unit to gain full access) flushed with clean fresh water until it ran clear. Removed the bleed valve on top of the water pump filled with new coolant until it ran through done it all back up.

However driven the car 30milies there and back so 60milies 3 nights in a row and the coolant remains freezing cold doesn’t get even a tad warm. Yet the engine is hot pipes are hot the 1s I can reach have fluid in. there warm up to the pipe on the right hand side of the rad (the pipe I used to drain the system) is there air in the system still or has something decided to die? If so any ideas or ideas how I can test it or remove air etc that is causing me problems?

Oh forgot to mention it drained loads from the system however I only filled it with approx 4.5 ltrs of antifreeze, thanks in advance