ok, disconnected battery and that didn't do anything. water pump is working fine and have got no leaks. garage did the pressure test and said that came back normal. next option is to take off dash to get to valves at back of radiator.....not looking forward to that. ordered a manual off ebay so hopefully will be here soon.
rockhopper, when it first overheated i was on the motorway and managed to get it back home (15min journey from work). the water temp went right up to max then dropped back down when fan kicked in and then same again. when i got home i filled up with hot water as tank was empty - took about 2 to 3 litres from what i can remember. since then though i've had no heat. now and again the water temp starts to increase and when i take the cap off, hot water bubbles out.
when i took it to garage i explained everything that had happened and they carried out all tests, pressure, gasket, flushed the hoses, etc and even did a power flush as theres some gunk in the water tank. they're a bit confused as they can't figure out what is wrong as everything they've tried has not been the problem
could it be that i've got an airlock?