Either the screen is clogged, or maybe the aux pump isn't pumping.

Pull the electrical connector off of the monovalve....this should give you full coolant flow...ie full heat. If nothing happens, unscrew the 4 screws, and pull the valve out - note the order in which the part go into the hole.

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It is a truism that almost any sect, cult, or religion will legislate its creed into law if it acquires the political power to do so. Robert A. Heinlein


09 Jetta TDI
1985 300D