Heat issues today. -2F

[EVJoe]

For the fogging issue. AC needs to be on to remove moisture from the air.

Would it run the AC when it needs it in Auto mode?

Sponsored

 

[RickMachE]

Would it run the AC when it needs it in Auto mode?

Yes.

 

[Teslaeata]

Would it run the AC when it needs it in Auto mode?

Only if AC is also turned on.

 

[AKgrampy]

I have always found Auto to be problematic when it gets really cold. I run at 68 - 70 at fan speed of 4. If I use Auto my car fogs up pretty bad. I just have to switch off floor fan and fogging will clear up fairly quickly In manual mode. Then go back to both floor/defrost after things clear up. I will also note that since the last OTA that was supposed to be an improvement in climate control that my fogging issue appears to have become worse - not better. I will have to give Auto another try. All that being said I have been comfortable down to -35 for around town driving with no frost build-up on rear windows. I drive a 22GT.

 

[MrFord]

It is definitely more a function of highway vs around town, and the mass of air to warm up entering the car. I'va had my '23 for a year and half, and drove it down to -40°C in northern Quebec last winter; it can keep the cabin nice and warm around town, but once you get on the highway, the PTC heater can't keep up with the rush of cold air coming in the car, plus the cooling effect of the air against the windshield and windows.

Temps got down to -20°C last week, and it seems to happen around that temperature (around 0°F), especially before sunrise. I keep my settings in Auto, 20°C, and lowering the Auto fan to 1 does help, as it reduce the amount of air entering the cabin to warm up, but after 30 minutes or so, you can feel is slowly cooling down inside. I had some frost bulding up on the windshield, but not enough to be an issue; once you have to slow down (in town for example), it starts catching back up. I've monitored the PTC over CarScanner, and it will stay pegged at 5.5kW; you can also watch the battery temps slowly go down (something to watch for, as I had an issue one time with it going down to -20°C, which triggered Turtle mode at 35%!).

I'm hoping that the heat pump, being more efficient, may struggle less with keeping up with the demand; I'll be curious to see some results over the winter for '25 owners. Otherwise, the car performs great, and it is a nice change to get heat almost right away when you leave on a cold morning. And if you've driven an ICE car, most of them struggle to keep the cabin warm below -30°C on the highway, so it is not abnormal; but there's definitely room for improvement.

 

[noway]

For the fogging issue. AC needs to be on to remove moisture from the air.

AC does not work in temperatures below freezing in any setting. This sometimes causes the fogging at start issue as AC would disable immediately after it detects the low temperature after leaving a heated garage

 

[Lohugo]

The heater will supply the battery pack primary and secondary supply heat to the cabin.

 

[Mach-Lee]

'23 premium, Heated garage parked overnight, departure times always on in the winter. This morning on my way to work I had very little heat. This is also the first day this year that its been below 0F. I normally run the temp at 72-74 with the fan on 2-5, mix of defrost and floor. Today I left when departure time was ready. When I left the blower was on 5 and the heat button was on and I had defrost and floor selected. I ended up having to switch to all defrost almost immediately when I pulled on to the road as the windshield started fogging. A few miles in I turned the temp setting all the way to HI and also had to set the fan to 7 to keep the windshield from fogging. If I selected floor and defrost then the windshield would fog even with the blower on 7. I felt up near the defrost and it was blowing warm air but not hot air. It was cold enough that the rear side windows started to frost on the inside. We passed through a few areas where the temp got to -10F. at that point I had to but my hat back on and if I didnt have the heated steering wheel on I might have needed gloves. Are these cars just this bad in cold temps or do I have some other issue? I am almost positive that if I take it to the dealer that they wont find any issues as by the time I get there it wont be below 0 any more and it will probably blow heat just fine.

Do not turn up the fan speed when it's very cold, you will cool down the cabin from all the cold air being sucked in. That was probably the main issue. In extreme cold, keep fan speed 3 or less.

Use AUTO, if the window is fogging up tap the regular defrost button, if it doesn't take care of it, then hit the MAX Defrost button. As soon as the frost is gone, put it back in AUTO or you will keep losing heat.

At -10ºF, heat will be limited. That's about where I start losing cabin temp, it might only be able to maintain 60ºF in the cabin.

 

[EVJoe]

So, I have been using the auto mode as people have suggested, and it’s been working but the weather has been fairly mild. This morning it was snowing and blowing and the temp was 13F(not below 0). I did like always and used departure times and pulled out of a 45F garage. With the hvac set to level 1 auto temp 75 with the regular defrost selected and the windows started to fog within minutes. I set it to auto mode 2 with defrost selected and that still did not work. I would select max defrost and that would get the windows cleared, but when I turned the max defrost off and only regular defrost selected the windows would start to fog within about 30 seconds. I tried on and off with max defrost about 8 times then gave up and I just left it on Max defrost and finished my drive to work. It was warm in the car, but not hot for having it on max defrost all the way to work. I also verified that my coolant tank under the hood is full to the line. I guess I’m going to bug the dealer and try to get my heater replaced. If people are not having and issue in sub zero temps then I must have some issue if I cant get hot heat at 13F and struggle to keep the windows clear without max defrost.

 

[Balsam Bob]

I live in northern Wisconsin and I would say that what you are experiencing is rather normal when the temperature is exceptionally cold. It was 1 degree F here yesterday. I left my heated garage with a 90% charge to go on a 15 mile trip. Within about 10 minutes the battery dropped to 68% charge - which I would say is normal. The side windows frequently fogged up. I keep climate control on auto, but I also need to use max defrost in these conditions. Max defrost typically clears the windows quickly so I turn it on for a few minutes and then off until they start fogging again - then rinse and repeat. Now that I'm accustomed to it, it's not a big deal to me - and, over time, the humidity in the car drops and the fogging lessens or goes away. It sounds like your heater is working, so I'm not sure your dealer will be able to help you.

 

[Mach-Lee]

So, I have been using the auto mode as people have suggested, and it’s been working but the weather has been fairly mild. This morning it was snowing and blowing and the temp was 13F(not below 0). I did like always and used departure times and pulled out of a 45F garage. With the hvac set to level 1 auto temp 75 with the regular defrost selected and the windows started to fog within minutes. I set it to auto mode 2 with defrost selected and that still did not work. I would select max defrost and that would get the windows cleared, but when I turned the max defrost off and only regular defrost selected the windows would start to fog within about 30 seconds. I tried on and off with max defrost about 8 times then gave up and I just left it on Max defrost and finished my drive to work. It was warm in the car, but not hot for having it on max defrost all the way to work. I also verified that my coolant tank under the hood is full to the line. I guess I’m going to bug the dealer and try to get my heater replaced. If people are not having and issue in sub zero temps then I must have some issue if I cant get hot heat at 13F and struggle to keep the windows clear without max defrost.

You can bring it to the dealer and ask if they could update the HVAC module software, that may improve fogging performance. But if you have a lot of moisture in the car (such as wet floor mats) you may be prone to getting a lot of fog.

My garage temp varies (about 10-20 warmer than outside) but when I leave in the morning I don't have any fogging problems (but I use departure times and remote HVAC so everything is warmed up when I get in). I use 68ºF AUTO 2 (nothing else selected). I rarely need to use the defrost button (don't select it unless you need it, same with other modes, just default AUTO).

The heater is probably fine unless you still have a problem keeping the cabin warmed up. In these temps it's important to plug in and use departure times or remote HVAC from the app to get the car warmed up a little before you leave.

 

[Mach-Lee]

I live in northern Wisconsin and I would say that what you are experiencing is rather normal when the temperature is exceptionally cold. It was 1 degree F here yesterday. I left my heated garage with a 90% charge to go on a 15 mile trip. Within about 10 minutes the battery dropped to 68% charge - which I would say is normal. The side windows frequently fogged up. I keep climate control on auto, but I also need to use max defrost in these conditions. Max defrost typically clears the windows quickly so I turn it on for a few minutes and then off until they start fogging again - then rinse and repeat. Now that I'm accustomed to it, it's not a big deal to me - and, over time, the humidity in the car drops and the fogging lessens or goes away. It sounds like your heater is working, so I'm not sure your dealer will be able to help you.

FYI, dropping from 90% to 68% in 10 minutes is not normal. Should only use 10-15% in that timeframe. Are you leaving it plugged in?

I usually see an initial 2-3% drop but then goes down at a normal rate afterwards.

 

[TheRock]

I had this problem during holidays. When driving down on the highway almost no heat. Thankfully it was sunny -15c. Full heat came back 1.5 hours later and it was -10c. Same when we left our hotel couple days after -20c. Full heat came back after an hour of driving. Will test this weekend when it's going to be -27c--20c

 

[Billyk24]

I had this problem during holidays. When driving down on the highway almost no heat. Thankfully it was sunny -15c. Full heat came back 1.5 hours later and it was -10c. Same when we left our hotel couple days after -20c. Full heat came back after an hour of driving. Will test this weekend when it's going to be -27c--20c

without any report on battery temperature, can I (we?) guess the vehicle diverted heat to the battery pack for warming at the expense of cabin heat.

 

[TheRock]

without any report on battery temperature, can I (we?) guess the vehicle diverted heat to the battery pack for warming at the expense of cabin heat.

I guess so but what's weird is only on the highway and with preconditioning...

Sponsored