How to fix a non-functioning heater in an Audi 80?

My Audi 80's heater is not working, what should I do?

First, check if there is enough coolant in the system. If not, add more and see if that solves the issue. If that doesn't work, check the fuse and replace it if necessary. If all else fails, it may be an issue with the heater core. It's best to take it to a mechanic for further inspection.

It could also be an issue with the thermostat. Make sure it's functioning properly and replace if needed. Another possibility is a clogged air filter, so it's worth checking and replacing if necessary. If none of these solutions work, it's best to take your Audi to a professional for a proper diagnosis.