Heater Control Valve issues? Passenger side blows cold air

[weareweird69]

So, this is something I can ask here that anyone can check on their F15.

We've had a random "NO HEAT" coming from the passenger vents whenever you shut the vehicle off, and then restart within the next 10 minutes to 20 minutes after shut down. Its done this pretty steadily this winter, and a few times in the past before this winter, but maybe once or twice a winter.

See Link for the image of the heater valve, and hoses, along with identifying numbers.

https://www.realoem.com/bmw/enUS/sho...diagId=64_2003


I went and felt the heater hoses to the heater core in the firewall from the heater control valve. One was warm (Number 2), I could hold my hand on it all day, the other was hotter (Number 1), and I don't think I could hold my hand on it all day. The difference wasn't a lot, but noticeable.

I also noticed that the one line (Number 2), top hose facing the front of the vehicle, was jumping severely, and it was very noticeable. I could feel the jump in the source hose from the auxiliary water pump as well. That is the bottom hose, towards the front of the vehicle (Number 4). Almost as if the valve was opening and closing quickly.

The line jumping is one of two supply lines to the heater core in the firewall.

Another power cycle later, with about a 20 minute off period, produced heat again in the passenger vents. The line was still jumping, but I noticed it being warmer this time, about the same as the other supply line to the heater core.

So, This brings me to a few questions, and maybe someone can check their X5 for me too. The heater control valve is on the drivers side, mounted to the inside of the fender, straight down from top/center of the shock tower. If you follow the heater hoses from the firewall, you'll find it easily.

Does any of your heater hoses jump, with the car warm, and the heat on?

Has anyone had any issues with their heater control valve?

Ive seen where these have been an issue for other BMW vehicles, and older X5's in the past, but haven't heard of these issues with an F15. Hate to buy a new valve for almost $200 and it not be the issue.

Setting the passenger, or drivers side to FULL HOT, and setting the thumb wheels to full hot makes no difference in the passenger vents. Coolant is full as well. The heater control valve's themselves were very hot as well.

So, do I have a heater control valve issue, or a blend door inside the dash issue?

[weareweird69]

Guess no one has had an issue of the one side being cold?

[Sophisticated Redneck]

Originally Posted by weareweird69

Guess no one has had an issue of the one side being cold?

Yep it's your heater control valve. Similar thing happened on my e70 (same heater control valve used in both e70 & F15). Just swap it out an you will be good. F15's are still a bit to new for these to start going bad in large numbers but in the next few years more and more will start popping up, right the 7-8 year mark is when they go out.

[weareweird69]

Originally Posted by Sophisticated Redneck

Yep it's your heater control valve. Similar thing happened on my e70 (same heater control valve used in both e70 & F15). Just swap it out an you will be good. F15's are still a bit to new for these to start going bad in large numbers but in the next few years more and more will start popping up, right the 7-8 year mark is when they go out.

Thanks for the reply. Most of the time, it seems that its the drivers side that loses the heat. So I wasn't sure!

[feven1026]

mine is at driver side. blow cold air while turning to heat. passenger side is normal

[bivash]

Any updates on this? Did replacing the heating control valves resolve the issue?

[SMIK90]

Sorry to resurect such an old post, but I'm having an issue where the driver side blows hotter air when running the AC, and I have a code in the hvac system for driver side water valve being stuck.

Would replacing this be a step in the right direction?

[Jakesax]

I've been noticing with mine that if I've had it blowing cold then turn the temp up it stays cold unless I turn it to max heat. Really annoying when on a long drive my hands end up numb 😂. Didn't realise this was actually a thing!