2004 Range Rover Temp. Gage is all the way to the end (red

My 2004 Range Rover radiator hose pope out of its place, the ring that holds in place became gave up apparently. I put the hose back with a screw tight clamp (as you know the ring that holds the hose fixed in place by the factory and does not have a screw). Then I added water while the engine was running and bleed it too. The Temp. Gage still goes to the end (red zone).
I am wondering what could be wrong. First I suspected that the problem is Thermostat, but that does not make sense, because I had the car cool off over night and when I started it this morning the gage went to the end on an absolutely cold engine right away.
Do you know what this what could be the problem and what do I need to do to fix this problem. I need to fix it temporarily so I can drive it to the shop to have them replace the hose.