Problem with heater in 2000 I30

[mike312]

Hi All,

I am having a problem with my heater and wanted some advice on how I might be able to fix it. The fan and air conditioning work fine. When I am driving on the expressway with the heat on I can feel hot air coming out of the vents as expected. Perhaps even warmer then I would expect. However, if I am sitting idle or stopped at a light, the system will just blow cool air. Which I suspect is how cold it is outside

Any advice or ideas?

Thanks

[NutriaforBreakfast]

Maybe your heater core is beginning to stop up?

When did you last flush your radiator?