Thanks for that guys but after further investigation it seems that its not just turning the heater on that cases the temp gauge to rise; if I turn on anything drawing a bit of current i.e. heated rear windscreen or headlights it does the same thing :confused:

Hi all, I've been surfing the foru for a while now but decided to join in the hope that someone can help explain a problem I appear to have. My series 1 Disco 200Tdi's temperature gauge 'appears' to climb 2 or 3mm above norm (straight down) when I turn the heater on. On turning the heater off...