VW Polo 1.4 CL petrol, automatic car has just had the thermostat replaced and is now blowing COLD air and NOT Hot air from the internal vents, when air blower switched on. Cannot see any blockages, as pipes are off. The car fan does come on okay, and car only slightly overheats still on when in idle state after a while the needle goes quite high.
But whilst driving, it does NOT overheat at all as temp needle stays constant at 70C in middle - but still only givesd and blows COLD air from the internal switch, to keep the window clear or myself in this cold weather.
Can anyone suggest or help ?

Terry, October 2010

Might be an air lock in the cooling system.

This seems the most likely cause as you are not getting any heat into the car.
Need to bleed the cooling system with the heater on, may be an air lock in the heater matrix.

Maurice, October 2010

Cold Air Coming Out Of INTERNAL Heater Vents
I always have cold air blowing out of my internal vents, when the temperature is adjusted. It's just COLD air only. Do I need a water pump at all as the next step? Thx

Terry, October 2010