check you have coolant and also check if there is pressure in the coolant tank, a traped thermostat would either make the temp guage rocket up or stay cold all the time depending on if it is trapped shut. i had this problem and it turned out to be a cooked head gasket. what engine is it?

Check the cable from the hot/cold switch, it might have come off at the matrix end and be stuck on cold.

no the temp gage only sits high when i am at a standstill with my engine running. so may not be the water pump

wot about the thermostat???

Water pump, coolent fluid. Heater wont work if they are broken, I had this with mine and the water pump had gone.

Does you engine temp gauge sit quite high?

yer could be, some of that rad stuff my solve it

maybe an airlock in the matrix thingy ?

sup, my heater has not been blowing out hot air for a while now, a while back my center consoul ligths when out and the heater decided it wouldnt blow out hot air anymore. its bloody cold now, any ideas about what the problem could be?
would it be the heater matrix and a blowen fuse or a lose wire, i am not sure.

cheers mike