Hot air from vents on A/C settings

[ColaBay]

I thought there was a thread and I can’t seem to find it. Anyway , we noticed that when A/C is running ( outside 95, inside setting 74 (auto), suddenly front vents will start blowing hot air for seconds or minutes and then it will go back to blowing cold air. It seems it is trying to hold a temp in car and it thins it is too cold (speculating) .

Anyone else noticed this or my car has a defect ?

 

[Lazyguy71]

I thought there was a thread and I can’t seem to find it. Anyway , we noticed that when A/C is running ( outside 95, inside setting 74 (auto), suddenly front vents will start blowing hot air for seconds or minutes and then it will go back to blowing cold air. It seems it is trying to hold a temp in car and it thins it is too cold (speculating) .

Anyone else noticed this or my car has a defect ?

I have similar experience.

 

[ColaBay]

Looks like only 2 of us are having this issue ! I will mention this to service center on my next visit. Based on readings on tesla forums for model 3 and model S , we may have to live with this. It seems car is trying to stick to a temperature instead of recognizing that intent was to cool the car and if it gets a bit cooler than the setting then it just need to use low fan and just air instead of turning on heater. it also may save some battery.

 

[philw1776]

I thought there was a thread and I can’t seem to find it. Anyway , we noticed that when A/C is running ( outside 95, inside setting 74 (auto), suddenly front vents will start blowing hot air for seconds or minutes and then it will go back to blowing cold air. It seems it is trying to hold a temp in car and it thins it is too cold (speculating) .

Anyone else noticed this or my car has a defect ?

Same issue with my Y
Plus, if say AC is on and set to 74 and I decide to lessen the wattage drain on AC by turning up to 76, it blows HOT air. That one seems like a software issue to me.

 

[im4uttx]

Not an issue, it's a feature. I think other threads mentioned turning down the fan to control comfort level instead of turning the temp up, especially above about 70F. Probably something that can easily be added with a software update to NOT change the "mode" of AC to maintain temperature...

 

[DFibRL8R]

+1 for a software fix if it is a “feature”, drove my better half (and by association me) nuts on our first road trip.

 

[Matsayz]

Go read this thread: 3rd A/C failure

also if you’re having issues schedule an appt via the app

 

[DFibRL8R]

Go read this thread: 3rd A/C failure

also if you’re having issues schedule an appt via the app

Not helpful, that thread is about intermittent total AC failure which is not what I have experienced. So far, the AC works well even with extreme heat in the car. The issue is when making slight upward adjustments in the cabin set temp (or when just holding the temp steady), the vents seem to briefly blow hot air which is unpleasant. If this is just how the system works and is not a defect, a service appointment would be a waste of time (other than formally logging that the issue exists and warrants future firmware correction).

 

[Matsayz]

Not helpful, that thread is about intermittent total AC failure which is not what I have experienced. So far, the AC works well even with extreme heat in the car. The issue is when making slight upward adjustments in the cabin set temp (or when just holding the temp steady), the vents seem to briefly blow hot air which is unpleasant. If this is just how the system works and is not a defect, a service appointment would be a waste of time (other than formally logging that the issue exists and warrants future firmware correction).

That thread has plenty of info on the whole clusterfuck that is the HVAC in the Model Y... so sure it’s helpful to read to read others experiences with this issue and what came from it.

Also, schedule an appt if you’re having issues. If you’re not the engineer who built the system or the one who coded the software then you have no idea why it’s doing what it’s doing.

Doesn’t matter if it’s a Tesla or a Ford, if you’ve got an issue take it in for service. Logging these issues is how fixes are pushed and parts are recalled.

 

[DFibRL8R]

That thread has plenty of info on the whole clusterfuck that is the HVAC in the Model Y... so sure it’s helpful to read to read others experiences with this issue and what came from it.

Also, schedule an appt if you’re having issues. If you’re not the engineer who built the system or the one who coded the software then you have no idea why it’s doing what it’s doing.

Doesn’t matter if it’s a Tesla or a Ford, if you’ve got an issue take it in for service. Logging these issues is how fixes are pushed and parts are recalled.

Yep, read the whole thread and there were no posts about this particular issue. And your advice on how you think I should use Tesla service is unhelpful. I own 3 Teslas and have used a Tesla service dozens of times over my seven years of ownership. I find leaving unhelpful advice on a forum obnoxious.

 

[newtnyc]

This has happened to me a couple of times. Climate was set to auto. Switched to AC and continued to blow hot air for a period of time before gradually cooling down. This seems intentional. Anyone else have any thoughts? Could it be a conflict between battery cooling v cabin cooling?

 

[Matsayz]

Yep, read the whole thread and there were no posts about this particular issue. And your advice on how you think I should use Tesla service is unhelpful. I own 3 Teslas and have used a Tesla service dozens of times over my seven years of ownership. I find leaving unhelpful advice on a forum obnoxious.

Cool story bro

 

[philw1776]

This has happened to me a couple of times. Climate was set to auto. Switched to AC and continued to blow hot air for a period of time before gradually cooling down. This seems intentional. Anyone else have any thoughts? Could it be a conflict between battery cooling v cabin cooling?

I think so. ^^^ For some of the issues mentioned.
But there's at least another anomaly that I say has a software cause and potential software fix. When using AC cooling, I decide that 74 is using too much wattage so I raise it to 76 foolishly thinking that the AC will simply shut down until outside heat raises the cabin to 76. Like in a normal car. Wrong! Instead, some software engineer deserving unemployment has coded the system to turn on the heat blasting hot air until 76 is reached.

 

[pkitch]

I've also experienced this a couple of times and also agree it's unpleasant. It's happened to me twice, both in the last week, never in the 2.5months prior of owning the car, hoping it's a software bug that gets smoothed out.

For me I have been able to 'fix' it by immediately turning the temperature to Lo, once it starts to blow cold air again (usually just a few seconds), then switch back to my previous temperature (around 68-70 on Auto) and that corrects it. I can't say for how long as not making many long drives lately...

 

[Ericna]

I thought there was a thread and I can’t seem to find it. Anyway , we noticed that when A/C is running ( outside 95, inside setting 74 (auto), suddenly front vents will start blowing hot air for seconds or minutes and then it will go back to blowing cold air. It seems it is trying to hold a temp in car and it thins it is too cold (speculating) .

Anyone else noticed this or my car has a defect ?

I think it has happened to me, I need to get a couple meters to leave in the car to prove I am not crazy though...

 

[Lazyguy71]

Just got 2020.32.3 update and the AC seems working much better. Have a trip with outside of 84F and the AC was set to 73 and I feel the cold air. Used to set to 72 or below or warm air could came out.

 

[pkitch]

Just got 2020.32.3 update and the AC seems working much better. Have a trip with outside of 84F and the AC was set to 73 and I feel the cold air. Used to set to 72 or below or warm air could came out.

OK this is good news, I received the update yesterday and only had a brief drive today and didn't notice anything different (or the temporary warm air issue we're largely discussing here), will take it out for a bit longer tonight and see...

 

[newtnyc]

So, it turns out that when the AC is set to manual - the air temperature is still blowing at the temperature seen on the screen. Yesterday, I had the AC set to Auto and 73. I switched to manual, turned the fan way up, and the air was not blowing cold as I thought it might. I kept the AC on manual and lowered the temp to 65 and the blowing air temp immediately got cooler.

 

[RoBoRaT]

So this is also (has been) happening to my car, VIN8XX Mar/2020 build, retrofitted with heat pump blanket Aug 6th, on 2020.32.3.

I tested it tonight inside my garage - garage temp 82°F.

See attached pics.
First I set the temp to 72F, AC on, Auto.
Car cools cabin to 72F.

Set temp to 73, still cool air. Fan at 4.
Set temp to 74, still cool air. Fan at 4.

Set temp to 75, garage temp at 82F.
Pump/Air blower blasts hot air (red) at Fan 6.

My car turns the heater (blows hot air) at 75F onwards regardless of outside temp.

 

[Lostthebeat]

As a complete Tesla noob who hasn't received delivery yet, may I ask if this situation can be resolved by leaving A/C setting in "Lo"?