I have 2006 Kia Sorento and the heat doe not work when not driving, but works driving down the road
your coolant loop is garbaged up with old coolant...change the coolant immediately...put a new thermostat in and cross your fingers that the heater core still runs free~
I tried the coolant loop, did not help. Took to a mechanic and had to replace headgasket. My heat works great now. I'd suggest to anyone having this problem to replace your head gaskets.
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