Hi Everyone

this is my first post so i hope i'm posting in the right place,my question goes as follows:

I have a 1995 Audi A6 and it would appear the heat works only when i hit the gas.. i really don't have any idea how can this be.. it seems to be a weird issue to me.. I'm even thinking perhaps has something to do with the cpu or something with the electirc system, I don't know where to start or what to check as the heat seems to be heating no problem but just when i hit the gas.. any help will be highly apprecciated

 

thermostat? $$$$

bad heater core? $$$$

low coolant level? (even a little bit down makes a difference) $$

 

Well it appears i got all that checked.. and no luck.. any other ideas someone can help me with so i can put them to work ?