Heater has gotten less effective over time in the few years I've owned the Jeep. With the dial set all the way to hot, it blows lukewarm air most of the time even when the Jeep is up to operating temp. Switching to recirculation doesn't make much difference. Noticed the air is significantly colder coming out the left-side vents, both floor & dash.

When I first bought the Jeep, the heat was awesome -- it was uncomfortable to put your hand on the vent, it was so awesomely hot. Not anymore.

I'm taking it in for service later this week. I have the extended 5-yr warranty. Will follow up with what they do to fix it. Coolant level is fine. I've seen reports that heater core sludge is pretty common. We'll see.