Today I noticed my water temp guage went up to virtually the top, I opened bonnet and everything seemed as normal. I decided to drive the short jorney home and the temp came back down to normal and went back up again.
When I arrived home I switched engine off and then back on and the temp was stayin at normal level.
Would this be a knackered thermostat? As soon as car cools down a bit I will check water level

 

Just checked water and it was low. Topped it up but it keeps emptying so would this be a leaking rad?

 

Could be a leak anywhere

 

check for bubbles in the expansion tank, when warm (normal operating temp)

 

Usual culprit is the plastic end tank on the radiator. Check for a wet bonnet lining or anywhere on the left hand side of the engine. If no leaks then it could be the head-gasket, which can be identified by looking for bubbles in the header tank, or sludge around the oil filler cap.