View Full Version : Heater control valve

04-19-2008, 01:11 AM
Has anyone been noticing lately or for a while that when the temp. button is on cold it is still blowing hot and there is no cycling between hot and cold and the AC works but still blows hot? I'm a tech just seeing how many owners have been or had this problem.

04-19-2008, 05:13 PM
I had this problem on a C220 but haven't on the Sprinter.

04-19-2008, 05:20 PM
Only problem I have is I get hot air comping out no matter where the knob is set on the dial, until its all the way off, at which point it will blowe cold, cool or warm depending on the temps outside. I know this has been discussed many times, and that the temp guage is very accurate, but I really dont think it is, or at least not in mine. All temps feel the same, and I drive all day, every day, its hot all the time, or its off. When in the middle between red and blue, you would expect warm or cool air, not hot. The dealers think its working fine, and im guessing anyone would, so its useless to continue the fight that its broken. I guess open a window to get your colder air (at faster driving speeds)

And sadly, I believe my AC is broken yet again, or leaked all its fluids, one or the other. The dealer last year said they found my fluids leaked out due to bad seals. They ordered new ones, filled her up, and it worked. on thursday it was 16c at one point, and I wanted my AC (due to a job I just finished prior to that) but it was blowing no colder then regular vent :( The dealer better still fix this problem no charge, even though my van is off warrenty. It was on when they fixed it, and its broken again under a year later. They just better!

04-30-2008, 12:28 AM
Well yes sometimes these valves do stick and you get hot all the time no matter what. I've replaced 2 in 2 different vehicles in the past 3 weeks. They had intermittent cool air. The ac was on and working fine but heat all the time. If you pinched off the coolant line to the valve, you got cold again. Thus determining it was the valve, unless the control head wasn't switching or sending out the voltage change to the valve. Anyway, Thanks and I'm glad a few responded. Just a technician curious as to waht other people are seeing. :rad: