I had this problem once in a Honda. It turned out that mice had made a nest in the duct, which restricted air flow. Any number of causes could restrict air flow in or out of the blower. Use an inspection mirror to look into the ducts. Underhood facing the front of the truck, the heater fan squirrel cage is on top part of the firewall on your left. There are three screws that hold it in. You may have to loosen/move the washer fluid resovoir also. After the squirrel cage is loose, unplug the unit from the wiring harness. Now pop out the rubber cover from the electric fan motor. You'll be able to see the brushes and the shaft. These get dirty and lose contact. Use q-tips and some rubbing alcohol while spinning the fan to clean. Should work pretty good after that.
Your heater core is leaking, Need to REPLACE HEATER CORE.
If the heater blower has humming noise when motor is running, first check its capacitor. If the capacitor is fine, then the motor is the problem and may need to be replaced.
It could be coming from your heater core, may need to repair or replace it.
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.
The engine has to be running and warmed up for the heater to produce hot air. So yes, you need gasoline to get heat from your car (unless you have an electric car).
There are many signals to show the heater needs repair. When it is not producing heat but running still it may be a small part or a large one. IT could need a simple solution.
you need a new heater core
If it smells sweet ,it is coolant, and the heater core has failed. If it smells electrical you have a wiring problem and need to remove whatever is necessary to find cause.
No you can not, It is under to much pressure when engine is running. NEED to REPLACE IT.
You might have to try pushing the button for longer, or you might have a bad thermocouple.
Front heater core is in the dash, the rear heater core is all the way in the back of the vehicle. If you have steam coming out of the dash vents, the front HC is leaking. If you have steam coming out of the rear heater vents, then the rear core is leaking.
You will need to replasce the heater core.