Recirculating Heater???

[Crazy Dazz]

This is listed as a Build Option for the WQ, but what actually is it?

Does it just refer to the ability to recirculate air within the cabin?
(Something cars have had for about 50 years?)
Why list it? Is there a scenario where it would not be fitted?

Now, apart from idle curiosity, the reason I ask is that my XR4 has always had an irritating issue.
The heater can never be completely shut off. So even when the ambient air is relatively cool, it blows warm.
It's annoying when the weather is turning, and I'd be happy with just ambient air on my face (I always like coolish air blowing on my face) but instead it blows warm. Not hot, but noticeably above ambient.

So according to the dealership, this was a "European" feature supposedly designed to stop the heater freezing in Winter and splitting. (Supposedly it might otherwise be possible in sub-zero climates if you inadvertently ran the A/C to defrost without turning the heat up??)

Of course it's entirely possible they were simply lying through their teeth.

Has anyone else come across this?

Either way, does the XR4 use a heater tap that I could easily replace?