rear seat climate control - I can't get it to produce any heat
 

I got a 2008 gl 320 last weekend. I opted for the rear seat climat control package as one of the options ($1800.00). It is -17 C outside and I can't get it to give up any heat from the unit in the roof , above the second row seating. The unit infront of the second row seats between the passenger and drivers seat works fine, but my daughter in the 3rd row finds it too cold. Does anyone who opted for this package had any luck in getting it to produce heat? Or is this unit in the roof, only for summer air conditioning? I would think a "climate control package" would include both heating as well as airconditioning.
Thanks , Mandy

RE: rear seat climate control - I can't get it to produce any heat
 

The 3 zone unit bought does heating/cooling for first and second rows, but only offers airconditioning for the 3rd.