More than likely, your cabin air filter has a leaf stuck in it or is really dirty and needs to be replaced.
You will have only cold air coming thru your heater ducts if your core is defective.
behind the throlt body
under the big black box to the left of the engine
When you have the heater on, does it just blow any air at all? or no air?
it's in the back of the engine below the manifold and under the air box tube.
i just replaced the thermostat in 2004 Chevy truck heater works fine now
The Chevy Aveo has a low price, high fuel economy, standard cabin air filter, OnStar, Bluetooth connectivity, a sunroof, air conditioning, six speaker audio system, cruise control, satellite radio, keyless entry, and power windows and locks.
Your heater core is leaking, Need to REPLACE HEATER CORE.
Heater core changed three years ago,I changed Thermostat Heater still blows cool air.
If a 2001 VW Beetle does not have hot air coming from the heater there is a problem with the vehicles heating system. The heater core is malfunctioning and will need to be replaced.
Check both the heater core as well as the heater hoses for leaks...........
Check the air pressure in the tires, you have a soft tire.