Welcome to Tesla Motors Club
Discuss Tesla's Model S, Model 3, Model X, Model Y, Cybertruck, Roadster and More.
Register

Model Y Heat

czbuckeye

Member
Sep 24, 2020
72
34
Ohio
Trying to understand how the Model Y heater works. I am wondering if there is something wrong with my heater or if it is the way heat operates on an electric car. Typically, the heat works very quickly when preheating the car, but it will intermittently blow cold air and then hot air again to control climate. The cold air is very noticeable and it is enough to make my feet cold and not recover when it blows hot again. Also, when I get on the interstate it will blow cold air for at least the first couple of minutes every time before it will switch back to warm air again. Finally, the past couple of days I have preheated by car for about 10 minutes (very cold outside, around 15 degrees Fahrenheit), and when I get to my car it has not warmed up at all even though in do not have any faults. Is this typical operation of the heater or does service need to look into this?
 

popgodazipa

Member
Jun 20, 2020
75
37
Houston
I have a MS so may not be apple to apple....but no mine does not seem to have the issues you describe. I did have that issue in my Cadillac ELR, something defective, service folks fixed it.
 

jcanoe

Active Member
Oct 2, 2020
1,756
1,740
Maryland
How do you have the HVAC set? I suggest Auto, 70F, cabin air recirculate Off. At 15F you should precondition the Tesla Model Y for at least 30 minutes before driving. Use the seat heaters; turn on the seat heaters to medium or high during the preconditioning period via the Tesla app. If possible precondition while plugged in, especially if you charge at 240V at home, as this will conserve your battery charge for use while driving.

The Tesla Model Y requires heat for several purposes. First, the Tesla will warm the battery pack if it becomes too cold as it is essential when charging that the battery not be cold. Also, when the battery is not warm enough the Tesla cannot provide full power and also cannot use full regenerative braking although partial regenerative braking may be enabled until the battery has been warmed.

In the Model Y the battery pack is warmed with waste heat energy produced by the front and rear electric motors. The heat produced by the motors will warm the coolant within the drive unit. This coolant is then sent into the battery pack. The Model Y heat pump can also use the warm coolant to heat the passenger cabin. In addition to the warmed coolant the Model Y heat pump can also recover heat from other sources including the outside air and the Tesla onboard computer.

In cold weather, assuming that you adequately preconditioned the Tesla Model Y vehicle, the battery pack will be warm when you start driving. On longer drives the battery pack will cool off as the heat pump pulls heat from the battery pack to warm the cabin. Periodically the Tesla may use the electric motors to generate additional heat to warm the battery pack. What you experienced may be the effect of the battery pack cooling until the Tesla generates additional heat via the electric motors or recovers heat from other sources.
 
Last edited:

czbuckeye

Member
Sep 24, 2020
72
34
Ohio
I have the heat set to auto 70, when I am sitting still the climate control is working fine. Just sat in my garage for 20 minutes and it did not blow cold air once, only adjusted the amount of hot air that was blowing out. This is only occurring while driving, even when it is above freezing outside and I have preheated and have full regen. I have also noticed more nose coming from the front of the vehicle. Previously sounded like a fan running, now sometimes has a crackle and sounding like a fan with more of a rattle.
 

jcanoe

Active Member
Oct 2, 2020
1,756
1,740
Maryland
There is a known problem with the Model Y heat pump where the HVAC stops producing heat when the outside air is below ~20F. This has been determined to be caused by defective high and low pressure sensors in the heat pump. You should contact Tesla via your Tesla app, describe the issue so that Tesla can determine if your vehicle has defective pressure sensors.

If your Tesla has this issue, when the HVAC quits producing heat it does not start producing heat again until the next time you start out driving after preconditioning. The noises you hear from the front of the Model Y may be normal when the front drive unit is being used to generate additional heat.
 

kadify

Member
Nov 19, 2020
262
105
colorado
I had this. If the temp was set to auto and something reasonable (70 degrees let's say) it'll blow warmish air and then switch to cooler air. It was almost as if the car heats too much and overshoots 70 so then blows cool air to lower the temp and vice versa. It effectively works out that you're either too warm or too cool. Our car did that prior to the sensors giving out this past weekend. Haven't gotten the car back from repair because the sensors are backordered but will update if the issue is still there with new sensors.
 

czbuckeye

Member
Sep 24, 2020
72
34
Ohio
Good to know thanks for your help. I have service scheduled for this weekend for some delivery issues, now I don’t feel completely crazy to being this up at the appointment.
 

jcanoe

Active Member
Oct 2, 2020
1,756
1,740
Maryland
Good to know thanks for your help. I have service scheduled for this weekend for some delivery issues, now I don’t feel completely crazy to being this up at the appointment.
I recommend that you update your existing service request now so that your cabin heating concerns are fully documented prior to the scheduled service appointment.
 

Skibum10ec

New Member
Mar 2, 2020
3
0
New york
I’ve had similar issue with my feet feeling cool breeze yet rest of cabin seems to feel fine. Heater set to 64-68 in 30deg weather. I’ve only had car 3 days so not sure what’s normal as this is my first electric vehicle.
 

gallde

Member
Jun 30, 2020
17
0
Tarrytown, NY
Anybody know how long the HVAC pressure sensor SB fix takes? I know it requires depressurizing and repressurizing the heat pump system, so I suspect it's not a waiting-room stay, more like overnight. Would they give me a loaner?
 

WADan

Member
Sep 28, 2020
179
118
Bellevue WA
I’ve had similar issue with my feet feeling cool breeze yet rest of cabin seems to feel fine. Heater set to 64-68 in 30deg weather. I’ve only had car 3 days so not sure what’s normal as this is my first electric vehicle.
I had this problem until I figured out how to direct the air to the feet (in addition to the cabin). Touch the fan symbol, and the screen will show those options.
 

kadify

Member
Nov 19, 2020
262
105
colorado
Anybody know how long the HVAC pressure sensor SB fix takes? I know it requires depressurizing and repressurizing the heat pump system, so I suspect it's not a waiting-room stay, more like overnight. Would they give me a loaner?
I was told it was only 2 hours to do when I left my car to have it done. Granted they had my car for about 2 weeks because they were waiting on the parts to come in.
 

X-Chris

Member
Nov 21, 2020
44
23
VA
Have similar problem - car occasionally blowing cold air when it should be blowing heat. Took took to service center.

They did not do the pressure sensor fix. They say they ran 3 tests - thermal system performance test, heat pump performance test, diagnose thermal system test, finding no problems.

Basically they told me that I had the temperature set to 69 degrees which is “not very hot” and I should just turn it up.

I thought this was ridiculous- before bringing it in, I tested it by driving 20 minutes in 45 degree weather with the windows open. At the end of that drive it was still blowing cold air.

I think in my case the car is not correctly measuring the internal temperature. I told that to my SA, but nothing was found to be wrong.
 

jcanoe

Active Member
Oct 2, 2020
1,756
1,740
Maryland
Have similar problem - car occasionally blowing cold air when it should be blowing heat. Took took to service center.

They did not do the pressure sensor fix. They say they ran 3 tests - thermal system performance test, heat pump performance test, diagnose thermal system test, finding no problems.

Basically they told me that I had the temperature set to 69 degrees which is “not very hot” and I should just turn it up.

I thought this was ridiculous- before bringing it in, I tested it by driving 20 minutes in 45 degree weather with the windows open. At the end of that drive it was still blowing cold air.

I think in my case the car is not correctly measuring the internal temperature. I told that to my SA, but nothing was found to be wrong.
I have experienced the same thing; sometimes when the climate control is set to 70F the air from the vents is colder than expected. If I am only traveling a short distance further I just ignore the cold air, else I bump up the cabin temperature setting to 71F. In a few minutes the air from the vents is warmer. I think this is caused by poor tuning of the climate control system including attempting to always maximizing efficiency, over anticipating the effect of sunlight warming the cabin during daytime hours.
 

davraker

Member
Aug 26, 2020
89
49
Northampton, Ma
Same issue. Very annoying.

Sometimes it blows uncomfortably cold. And yes, if I then turn it up to 75 it does get warm again. But if I have to do this, what is the point of the Auto system?
 

About Us

Formed in 2006, Tesla Motors Club (TMC) was the first independent online Tesla community. Today it remains the largest and most dynamic community of Tesla enthusiasts. Learn more.

Do you value your experience at TMC? Consider becoming a Supporting Member of Tesla Motors Club. As a thank you for your contribution, you'll get nearly no ads in the Community and Groups sections. Additional perks are available depending on the level of contribution. Please visit the Account Upgrades page for more details.


SUPPORT TMC
Top