How to fix the heating system in Audi 80?

My Audi 80's heating is not working properly, how can I fix it?

Check the coolant levels in your car and make sure they are at the right level. Low coolant levels can cause issues with the heating system. Also, check for any air bubbles in the coolant system that may be affecting the heating.

Make sure the thermostat in your car is functioning properly. A faulty thermostat can prevent the heating system from working effectively. If needed, replace the thermostat with a new one.