BMW e46 Heater control valve check and diagnostic

A quick video in how to check the heater control valve on a BMW e46. The same valve could be also installed in other BMWs. The content of th video is applicable to most heater valves in many different car brands.

[@milivojmilosevic1172]

Thank you so much for this video ! I found your video while searching for a solution to my problem. My 2005 e46 325i does not blow warm air thru vents, only cold air.

[@Sp3NgL3R_MF]

Can you please tell me what is the part numbers for hoses that are connected to it ?

[@TheOnlyRaceEngineer]

great explanation. SUBSCRIBED

[@Ndzila-pl6qw]

great video...does this heater control valve also responsible for cold air? .... from Mzansi.

[@DIYTEA]

@@Ndzila-pl6qw No. Cold air will flow through the evaporator and this valve should be closed.

[@liambrindley9087]

The reason is that the valve is to help the passengers stay warmer even when the engine has stopped, its more of a comfort thing, i noticed when mine wasnt working properly as the cab heating instantly goes cold after shut off 👍🏼

[@kosteg83]

no, it's opposit. it's to avoid overheating of cabin when engine will be started again within 15min and heatcore will be filled with hot water from engine.

[@kosteg83]

According to technical data this 15min valve off is to avoid overheating of the passanger compartment for short stops. If you are going to fill up tank, engine off - when valve will be open heatcore will fill up with hot water and just after starting car again you will have a hot air blow. So, to avoid it, valve stays close to prevent of mixing water from heatvcore with engine water. In e46 there is no "rest" button on heating panel. There is no single function to control cabin tempereature when engine is off. And to be honest - e9x, e6x, or even e39 - with "rest"button - all of them to allow of adjusting cabin temperature when engine is off - they are using additional electric water pump and stays valve open/closed depends of needs.

[@DIYTEA]

Sounds very logic to me, thank you for sharing. In addition to the confort may be to protect the heating components from overheating.