sounds like it might be as simple as a leaf or twig has gotten in through the air ducts & vibrating on the a/c heater fan happens to me all the time depends were you park the car.
it doesnt work, it breaks it doesnt work, it breaks it doesnt work, it breaks
why doesnt my heater work on my1985 BMW
It has a lot to do with the fact that the heat provided when you turn the heater on comes from the engine. the faster your engine is reving the more heat you'll get. Next time try putting the car in neutral and revving the engine. that should get you some more heat.
Thermostat and/or heater core may be defective
You prob have to replace the heater core
The heater motor is failing.
its probably broken or not plugged in
COULD BE A BAD HEATER CORE COULD BE A BAD HEATER CORE sounds like the heater control switch needs replacing.if that doesnt fix it, you need new heater core
Corrosion.
The sun.
doesnt come with one try frostheater.com vw doesnt even make one for it
Low coolant? Bad thermostat? Heater core plugged,restricted or airbound? Heater control cable or valve not working?