Anemic heat

1997 Chrysler Town & Country minivan, 3.8 engine, 150,000 miles. Our minivan’s heater is very ineffective as of late–gives very little heat. When my wife does errands around town or drives my son to school she feels no heat from it at all unless it’s a long errand. This morning I traded cars with her, skipped mass transit and drove the van to work (50 miles, mostly freeway) and it took around 15 minutes before I felt any heat at all and for the rest of the trip the best word to describe that heat is “anemic”. You do feel air blowing–very little heat. Further background: It was around 20 degrees this morning and I saw the car’s temperature gauge rise the normal amount as I drove. I switched to defroster and different blends of bi level–no change in the amount of heat. The water pump and radiator fluid were both replaced approx 1 1/2 years ago. The radiator fluid is at the proper level. I don’t smell a leaking heater core or see radiator fluid on the ground. Any ideas? Thanks in advance.

You probably just need a new thermostat. Better stuck open than closed though. You being a little chilly is always better than an overheated engine.

What is the temp gauge on the dash doing throughout one of these drives?

The needle moved up to about halfway on the dial and stayed there the rest of the trip.

If the temp needle is behaving normally then it may not be the thermostat. That would point to your blend door not working properly.

Either that or both your thermostat and temp sender for the dash gauge are bad.

I’m guessing blend door.

There’s a door in the HVAC system that opens and closes to mix cold and hot air. Sometimes that gets jammed, and then you end up stuck with whatever mix it’s jammed at. You feel more heat later because at first the vents are cold enough to cool off the air before it gets to you. Later as the vents slowly warm, some of that warm air manages to stay warm as it goes through the vents.

Thanks for the info everyone. Any ideas as to where the blend door is in a Town & Country? I will try and follow the heater hoses but if it’s in the engine bay I’m guessing it will be near impossible for me to reach. If it’s in a part of the dash that I can more easily get to I may look at it this weekend. I’ll also do some online searches when I have some time.

If I recall, it’s behind the radio, and you have to disassemble the dash to get at it. This might be something best left to a professional. Dash disassembly pretty much sucks, especially when it’s cold, and it’s not hard to mar or crack things when you’re doing it.

A restricted heater core from sediment would be my first guess. In the past I have removed the heater hoses and flushed the dirt out with a water hose.

If you belive there is a problem with the HVAC control or actuators there is a calibration/seft test that can be performed but you will need a warm place to do it. During the self test the system also performs a cool down test and if the A/C evaporator doesn’t drop in temperature by 20 degrees the test will fail and your HVAC control buttons will be blinking. To enter the self test;

Set Blower motor ON HIGH
Set Mode position to Panel
Open all A/C outlets
Set Temperature to Cold (Both slide pots if equipped)
Depress WASH and REAR WIPER button simultaneously for 5 Seconds (Until all LED’s light)

After 2-3 minutes the calibration should be complete, if there are any faults detected the HVAC buttons will blink.

It could be a partially plugged heater core or an air bubble in the system if you recently got the coolant changed. If you can get to the heater hoses under the hood, feel them both when the car is warmed up. Both should be nice n’ hot. If one is a lot cooler, your heater core is likely plugged or there’s air in there somewhere.

It also could need resetting, as Nevada said. I used to have to do this in the summer on my 1994 Chrysler to get the AC to blow cold air before I replaced the climate control unit. You can also try turning the temp down to the minimum, wait about 5 seconds, then all the way back to hot. This also would work when my climate control was getting flaky.

Interestingly, when I drove home from work yesterday I had heat–plenty of it. This was after the van had been parked in underground parking for 8 hours (considerably warmer than the outside temperature). I realize it’s probably a matter or time before the problem returns. I’m interested in trying Nevada’s calibration/self test the next time I’m in a warm place.

Hope you dont need a new Heater core. YOu could try to drain your cooling system and add a cooling system flush chemical…then follow the instructions and flush your system …then refill and see what you get.

ALso look into that blend door thats a good idea but I am leaning twd sediment in your heater core. If you know what you are doing you can also pull a hose off the core under the hood and flush that directly…this will blow out anything in the core that will come out…sometimes nada comes out bec it is a scale buildup in there…

Has the coolant been changed regularly in this vehicle? If not…this is further reason for the rad flush and or core flush.