heater valve issues...

hi
i currently own a 96 318is e36
im suffering with the heaters, really become a pain in the winter that there is basically zero heat i will get a blast of warm air for about 15 seconds at motorway speeds then that is it the temperature sits fine on the guage and the pipes going to the heater control valve air boiling i have flushed the heater core and cooling system about 10-15 times my thought is obviously the heater control valve but why am i getting a blast of hot air sometimes then nothing? really would appreciate your reply as this is getting to me now thanks :

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This post was auto-generated based upon a question asked on our tech article page here: Pelican Technical Article: BMW Heater Valve Cleaning/Flushing

[Wayne 962]

Hmm, it could be a control unit issue, or it could be the valve itself. I would see if you could test the heater valve by applying 12 volts to it directly to see if it opens. You can also check the electrical connections by disconnecting the wires and checking them too when the control unit is supposed to be opening the valve.

- Wayne