I am going crazy! My heat is out again. I took it to the dealer who told me thate the climate control "duo valve" was bad. Well I bought one from the wrecking yard. I had heat for about a month. Heat is out again! I have replaced this Duo-valve three times. It makes me believe it is something else. Anyone have expierence with this?

HELP!!!!!!!!!!!!!!!

Gman

I cant tell you more, but the default for the duo valve is open, that means unless it gets a voltage to close is is open. It could stick shut but why, if you want heat pull the connector, it is probably your dash controller

Hi
I am not mechanically inclined, but I can try your idea. IS there a way to help with instructions ?

Best

Gman

This may help:
http://www.benzworld.org/forums/w140...duo-valve.html

I found it searching for "w140 duo valve" on my new Mercedes search site, powered by google. Give it a try for hopefully more help!

Peter how do you pull the connector. It is too cold not to have heat!

Thank you!!!!

GmAN

I'm another thin-blooded San Diegan, just discovering the heater. Other readers won't feel too sorry for us when they find out we are shivering in 55º weather.
Actually I just got my 96 S320 last week. It's near perfect and a great delight (after putting over 300K miles on a 126 that was a great, but comparatively primitive, car).
But please, somebody tell us how to make the air conditioner turn off and the heater turn on. The temp may plummet into the 40's!
And, the instruction manual's explanation aside, what do the little red and blue buttons on the center vents do?