Why is most of the text blocked out by these big solid grey circles all joined together like this OOOOO but in sold grey& vertical from top to bottom of the article.....you can't read all of the text...ridiculous!
The panels that contain the foot well lights can be unscrewed and removed that should allow you to be able to see what is going on. Have you removed the heater control knobs to see if they are still attached properly?
No I'm not sure how to remove them....do they just pull off. I've only just got this car & I don't want to break the control knobs due to ignorance.
To be honest I thought that the front panel which houses the control knobs & Stereo would be the panel to take out if possible.
The knobs do pull off, but are a tight fit, so care is needed to remove them without damage.
The knob that is loose probably has a split in the plastic and is no longer gripping onto the shaft. It will probably pull off OK as a result, and can easily be replaced with a good one from a breaker. There is a spring steel collar which keeps the plastic knob and shaft firmly together - make sure you get the existing one off before trying to fit a replacement (and if it is missing from the replacement, you can use it for that).
As you say the heat control knob turns alright, but does not alter the heat coming from the vents, it would suggest that it is probably the cable that has either become detached or is broken at one end or the other.