Moved to correct section.
There could be a blockage in your interior heating system.
Ive fixed it on a different car by simply taking the pipes of in the engine bay,spraying some water in and out the other side to flush it out.I did this until the water came out clean on the other side.Went from very little heat to good as new.
If however your gauge on the cluster isn't showing the car as heating correctly,it could be your thermostat.
If its using alot of coolant,it could be your headgasket.Check for white smudge under the oil cap and do a compression test to see if any of the cylinders are low.
Dan