Nissan Repair: Nisan Primera 2.2 dci. 03, nisan primera, heater control valve

Question
Hi
The heater is only blowing cold and no air is blowing onto the windscreen.  The air con. seems to be working normally.  Any ideas please?

Answer
Hi Keith -

I would check a couple things first -

For the cold air - There is a heater control valve connected in line with the heater hose in the engine compartment. This is usually run by an engine vacuum hose. Might want to check to see if that hose is not broken or disconnected. If not, check the valve itself for binding.

The air that blows for the windscreen is also controlled by engine vacuum, or it could be a stuck door in the ductwork that channels the air.

If these two happened at the same time, then check the main vacuum supply hose, especially if the engine is running a little rough. Supplying the vacuum again will fix both problems for you.

Hope this helps -
aloha
calvin