Is very weak rear heat normal on Model X?

[Big Earl]

rear heater in MX is unacceptably bad. Mine has been in the shop a few times and they tell me "try this setting; turn of that." doesn't matter. it's still no good and apparently no way to fix.

specifically, at 35F today I preheated the car for 45 minutes. then used rear heat on MANUAL/HIGH. I kept checking and got cold air out of rear pillar vent UNTIL after driving for 55 min. Tech said to turn OFF "range mode" so I did that and tried on the way home. same deal. except worse. the car was in my heated (70F) factory and plugged in. when I drove home the rear vents were still blowing cold air when I got home. No way the battery could be very cold when it was in a 70F space for 8 hrs!!

What fan speed were you using on the rear heat? I've found that anything over about 4 overwhelms the tiny heating element and the air coming out of the vents feels cool instead of warm. Someone else reported that their rear heat doesn't function at all, so you may have a problem with the system. Tesla should be able to see how much power the rear heating element is using and determine if it's functioning or not.

 

[drewg123]

What fan speed were you using on the rear heat? I've found that anything over about 4 overwhelms the tiny heating element and the air coming out of the vents feels cool instead of warm. Someone else reported that their rear heat doesn't function at all, so you may have a problem with the system. Tesla should be able to see how much power the rear heating element is using and determine if it's functioning or not.

+1 to this. Try running at one of the lowest fan speed (3 or less) and highest temperature. When it is really cold outside, that's the only we we can get heat in the back.

 

[jbwinton]

I have a new-config 7 seater and just got back from a week long road trip where the first and last days were done in "cold" (roughly 30F) weather. The front was reasonably comfortable, but my son complained about being cold in the 2nd row. I did some controlled tests after I got home.

In our garage, with the car plugged in, and ambient temps of ~55F, car interior at 60F according to the app, and with the front and rear both set to "hi", the front vents emit very warm air. The rear vents all emit luke warm air. I should probably get a better thermometer so I can quantify it. Shouldn't the rear vents also be blowing hot air?!?

One interesting thing I learned when playing around like this is that the 2nd row center vents (attached to the front row's center console) seems to be controlled by the front, not rear, climate control. It is treated as one of the upper front vents when controlling things manually. Is this expected?

Another "interesting" thing we learned on the trip is that the air temp emitted by the front vents seemed to vary with speed. Eg, the air was not very warm at 75Mph, but was nice and warm while we were sitting at the supercharger. As I'm writing this, I'm wondering if this could be due to range mode?

no matter what you do, the rear heater is no good in cold climates. i've been arguing this with tesla for months. after careful testing, it is clear that it takes 50 minutes (when driving 60mph) to get the rear pillar vents to blow warm air.....no matter what else i try as for the settings. dealer has checked several times and tells me there's "nothing that can be fixed." it's a design error; car was designed and tested in calif. and they forgot some of us live in cold climates!!