2021 Model 3 Heater blowing cold air

[Acxxu]

Update:
I will be testing (like the most of you, obviously) whether 2021.44.30.7 helps with the issue. Installed it earlier today, but alas it is a bit too warm outside today to get an effective test. At least with the previous 2021.44.30 the problem was still there.

Temporary workarounds:
1. Select from Tesla's navigation a near enough Charging station so that Battery Pre-conditioning appears (on a red background up top to the navi's waypoints). The preconditioning will very quickly deliver plenty of heat to the cabin, even during driving.

2. Stop the vehicle, change to Park-mode and turn on CAMP -mode. This will also very quickly bring the nice warmth back to the cabin.

Caveats:
1. Pre-conditioning: There may not be a Tesla-supported Charging station near enough for Battery Pre-conditioning to turn on. This will then require you to drive closer to it in order for this to happen. (Tesla increased the range of this activating several firmware releases back.)

2. CAMP: If you intend to be driving a longer distance, this doesn't really help you progress your trip, but at least you'll get some temporary warmth. As you resume driving, you'll only get cold air again. (Note: I've had some luck with the cabin receiving further warmth when resuming driving, but can't pinpoint why this happened when it did.)

 

[Acxxu]

Update:
Tesla Model 3 Performance (MY21), got mine among the first in Europe during the Christmas of 2020. It now has 31 500 km (19 500+ miles) behind me, I've been testing this, including over 13 trips to Lapland and back (1 000 km per leg / 600+ miles per leg).

I repeated my normal test-cycle today, having 2021.44.30.7 installed yesterday:
- heat car through phone app
- start driving, heat battery to above +12'C (+53.6'F)
- drive to a fast charger with less than 35% charge (SoC) without setting it as a target into navi (no battery pre-conditioning)
- charge up to above 90% without leaving the car/not locking the car (ended at 97%), make sure battery is above +55'C (+131'F)
- start drive-test at 100km/h for ca. 20 kilometers to see effect

This time, with the new software (2021.44.30.7) I actually had warm air coming into the cabin with AUTO +20.0'C setting. I drove further to see whether this was temporary, but I couldn't repeat the "coldness" as with all the other tests (same) I've done. I actually could warm up the cabin with +27.5'C and moving from AUTO to FAN setting at 10. Warmth! (Previously, this setting used to push only cold air to the cabin.)

This is a preliminary result, as it was only -2'C outside (+28.4 Fahrenheit), I will do further tests in a colder setting.

Interestingly, the Heat Pump did not turn on during my test (only the fan was making sound from the front). Hence, I believe the Octovalve was pushing warm air from the battery to the cabin. Tested this a couple of times to verify that the only noise came from the fan itself, the heat pump was silent.

Issue is potentially fixed by latest software update?

 

[Willy’sEV]

Yeah, you should just return the car.

This kind of comment adds nothing.

 

[Amped412]

https://twitter.com/x/status/1482464666643316741

Not looking good for some heat pumps

 

[texas_star_TM3]

if you run the motors inefficiently to generate enough "wasted" heat for the heatpump to even work in very cold temps... what are the savings over just going to resistive electric heating to begin with? heatpumps shine efficiency wise between 30F+ but in very cold temps they struggle.

 

[stopcrazypp]

if you run the motors inefficiently to generate enough "wasted" heat for the heatpump to even work in very cold temps... what are the savings over just going to resistive electric heating to begin with? heatpumps shine efficiency wise between 30F+ but in very cold temps they struggle.

Almost none. COP approaches 1 as the temp gets sufficiently cold. But that is not the issue at all, because at that point you don't really care about efficiency. The core issue with heat pumps is that given it has a COP of 3-4 normally, when it drops to COP approaching 1, you only have 1/4-1/3 of your heat generating capacity, which is not acceptable. That's why a lot of home heat pumps have resistive aux heat. Tesla (and some other heat pump manufacturers like Mitsubishi) gets around this by running the compressor inefficiently to generate excess heat, comparable to when the heat pump is running efficiently, making conventional resistive aux heating unnecessary (as it functions the same).

However, AFAIK the core issue in the Tesla heat pump from even a year ago is they had defective sensors (which shut down the compressor completely, so it is generating no heat at all), which I'm not sure they ever successfully redesigned (they had a TSB for this, but it doesn't sound like it was a permanent fix, it was just replacing the broken one with another one that is almost the same). That brand new vehicles are experiencing the same thing (I'm assuming they are, if they are not, someone please correct me), leads me to believe they haven't designed a part yet that fixes this permanently. I believe the issue is the sensors freeze up in sufficiently cold temps, which makes it so the compressor refuses to start. It's possible to bypass the sensors with various modes (I believe defrost or camp mode was mentioned) and I believe the software fix Tesla talks about essentially does that, but that solution is not a long term one (as presumably the sensors are still necessary to detect a real failure).
Tesla to Replace Faulty Model 3, Model Y Heat Pump Sensors

 

[texas_star_TM3]

Almost none. COP approaches 1 as the temp gets sufficiently cold. But that is not the issue at all, because at that point you don't really care about efficiency. The core issue with heat pumps is that given it has a COP of 3-4 normally, when it drops to COP approaching 1, you only have 1/4-1/3 of your heat generating capacity, which is not acceptable. That why a lot of home heat pumps have resistive aux heat. Tesla (and some other heat pump manufacturers like Mitsubishi) gets around this by running the compressor inefficiently to generate excess heat, comparable to when the heat pump is running efficiently, making conventional resistive aux heating unnecessary (as it functions the same).

However, AFAIK the core issue in the Tesla heat pump from even a year ago is they had defective sensors, which I'm not sure they ever successfully redesigned (they had a TSB for this, but it doesn't sound like it was a permanent fix, it was just replacing the broken one with another one that is almost the same). That brand new vehicles are experiencing the same thing (I'm assuming they are, if they are not, someone please correct me), leads me to believe they haven't designed a part yet that fixes this permanently. I believe the issue is the sensors freeze up in sufficiently cold temps, which makes it so the compressor refuses to start. It's possible to bypass the sensors with various modes (I believe defrost or camp mode was mentioned) and I believe the software fix Tesla talks about essentially does that, but that solution is not a long term one (as presumably the sensors are still necessary to detect a real failure).
Tesla to Replace Faulty Model 3, Model Y Heat Pump Sensors

thank you! We use a heat pump to heat our house - works in Texas but in a colder climate like Minnesota you'd be better off with a gas furnace as you would be running the auxiliary heat too much and negating any efficiency savings.

 

[SylvainG]

Almost none. COP approaches 1 as the temp gets sufficiently cold. But that is not the issue at all, because at that point you don't really care about efficiency. The core issue with heat pumps is that given it has a COP of 3-4 normally, when it drops to COP approaching 1, you only have 1/4-1/3 of your heat generating capacity, which is not acceptable. That's why a lot of home heat pumps have resistive aux heat. Tesla (and some other heat pump manufacturers like Mitsubishi) gets around this by running the compressor inefficiently to generate excess heat, comparable to when the heat pump is running efficiently, making conventional resistive aux heating unnecessary (as it functions the same).

However, AFAIK the core issue in the Tesla heat pump from even a year ago is they had defective sensors (which shut down the compressor completely, so it is generating no heat at all), which I'm not sure they ever successfully redesigned (they had a TSB for this, but it doesn't sound like it was a permanent fix, it was just replacing the broken one with another one that is almost the same). That brand new vehicles are experiencing the same thing (I'm assuming they are, if they are not, someone please correct me), leads me to believe they haven't designed a part yet that fixes this permanently. I believe the issue is the sensors freeze up in sufficiently cold temps, which makes it so the compressor refuses to start. It's possible to bypass the sensors with various modes (I believe defrost or camp mode was mentioned) and I believe the software fix Tesla talks about essentially does that, but that solution is not a long term one (as presumably the sensors are still necessary to detect a real failure).
Tesla to Replace Faulty Model 3, Model Y Heat Pump Sensors

Well, nope, the error code is VCFRONT_a447 and that's what I daughter got (mine was VCFRONT_a161 and although same result, less common) and when that happens, you can't use defrost and regarding camp mode, it will say 'Climate keep unavailable due to system fault' so that can't be used either. Luckily for her, they're taking the car right away and lending her a car in the mean time.

 

[stopcrazypp]

Well, nope, the error code is VCFRONT_a447 and that's what I daughter got (mine was VCFRONT_a161 and although same result, less common) and when that happens, you can't use defrost and regarding camp mode, it will say 'Climate keep unavailable due to system fault' so that can't be used either. Luckily for her, they're taking the car right away and lending her a car in the mean time.

I'm talking about cases where it blows cold, but haven't faulted completely yet. Example below of things working with defrost mode from the app:

https://www.reddit.com/r/TeslaModel3/comments/ry93ku

Camp mode working in this example, but blows cold in regular modes:
2021 Model 3 Heater blowing cold air

When you reach the point of getting actual fault codes, I believe the entire system is shut down to prevent possible damage, so there is no way to override that. That is a later stage of the failure, but most people are seeing the initial stage, where it just suddenly starts blowing cold air instead of heat.

 

[SylvainG]

Both our cases, we had heat, until we didn't and nothing to be done to get heat back, short of moving South lol.

 

[rpiotro]

Just to throw my 2¢ worth in here. Yesterday it was -1°F. The car seemed to warm up just fine. The climate hardware under the frunk was a bit noisier than usual though. I'm impressed. We have had temps here as low as -24°F just a few years ago. I suspect it will not perform as well. I'm not going anywhere anyway.

2021.44.30.7

 

[SylvainG]

Just to throw my 2¢ worth in here. Yesterday it was -1°F. The car seemed to warm up just fine. The climate hardware under the frunk was a bit noisier than usual though. I'm impressed. We have had temps here as low as -24°F just a few years ago. I suspect it will not perform as well. I'm not going anywhere anyway.

2021.44.30.7

It was -27C (-17F) last Thursday evening here and I drove 103 km (house to cottage) without my coat on. Temperature in the car was set at 21C (70F). My efficiency took a big hit though. What used to take 27% of the battery last fall took 52% Thursday. It's a good thing I didn't forget my charging cable otherwise I wouldn't have been able to drive back home! So I can safely say the 2021 M3 can handle cold well (as long as the heat pump doesn't fail) but it will impact the range big time.

 

[Randy-12]

It was -27C (-17F) last Thursday evening here and I drove 103 km (house to cottage) without my coat on. Temperature in the car was set at 21C (70F). My efficiency took a big hit though. What used to take 27% of the battery last fall took 52% Thursday. It's a good thing I didn't forget my charging cable otherwise I wouldn't have been able to drive back home! So I can safely say the 2021 M3 can handle cold well (as long as the heat pump doesn't fail) but it will impact the range big time.

27% to 52%
Was that change at the same driving conditions and temps? Ie before the updates a few weeks ago?

 

[LaneDS]

Not much to add to this other than yesterday I ran into this problem on a thankfully short trip.

I had turned on climate via the app (not the defrost option) before leaving while it (2021 M3 LR) was plugged into the wall charger. Heated fine. Drove 30 minutes to an appointment. 40 minutes later, on the drive back, realized I was just getting cold air on the return trip. Not a big deal in that case, but certainly worrisome. I'm on the .7 update from last week.

Are we all in the "wait and see what the official response is" stage? Worth contacting service, or wait to see if additional patches address it?

 

[SylvainG]

Didnt

27% to 52%
Was that change at the same driving conditions and temps? Ie before the updates a few weeks ago?

Didn't get this cold before the update so I can't compare.

 

[vesder21]

Is anyone having the same issue with earlier models - non heat pump vehicles?

My 2018 M3 blows warm air went on automatic mode but if you switch to manual it becomes cold. Not a huge issue since I leave it on automatic, but wondering if anyone else has experienced this issue!

I wonder if it’s a V 11 software issue?

 

[holmgang]

Is anyone having the same issue with earlier models - non heat pump vehicles?

My 2018 M3 blows warm air went on automatic mode but if you switch to manual it becomes cold. Not a huge issue since I leave it on automatic, but wondering if anyone else has experienced this issue!

I wonder if it’s a V 11 software issue?

Mine has issue where in most temp ranges, it blows cold / ambient air. Then at a few of the most extreme ticks, it would blow extreme hot air.

Problem was some sort of sensor. It was swapped and now hunky dory.

 

[Acxxu]

Update:
Over the rest of the winter I did face the issue(s) again, but quite peculiarly setting a (workaround) next destination (in navi) as one of Tesla's Superchargers did actually start to push warmth into the cabin (even when not getting the battery preconditioning message to display on screen). I believe also setting the navi to other than Tesla's own fast chargers had the same effect (even if you were driving in the opposite direction, like I was, in cold Lapland).

In addition, Camp Mode and similar tricks described above worked (at times). If you happen to have an early Model 3 with heat pump (MY21 from 2020/2021) and it hasn't had the replacement parts installed, you might want to heed to this workaround. (After supercharging on longer trips, it comes in handy, as after supercharging you cease to get heat..)

However, come 2022 summer and +26...+36'C degrees, the heating issues turned to cooling issues. I couldn't pinpoint quite exactly how to make the car cool, but it worked intermittedly. I did drive a full day in up to even +40'C (heat wave) in Middle Europe; especially during this particular day, cooling worked marvellously, thank goodness (I tracked the data with the "scan my tesla" -app and the OBD2/Bluetooth adapter quite meticulously over driving in Middle/Southern Europe for those 3 weeks). At best, scan my tesla showed under HVAC that the "Evap temp" went down to +2.70'C (no issues then) and on days when cooling only "sort of worked", it only went down to 17.8'C or slightly less (all the time Evap demand was at around 6500W, even 7475W or more). (Probably wasted quite a bit of energy in the process?)

When stationary, I got around to checking from the Tesla App whether temperature inside car was cooling or not, if not, I restarted the cooling by trying various combinations from the app - many times getting it to work "partially" (Evap temp dropped to <18'C degrees, but didn't go below +15'C or so). To my surprise, setting "Dog mode" very often resulted in no cooling coming to car/cooling to cease and my phone getting instant messages about the problem (nice feature, though). At this point I was confident that the coolant/gas was not fully blown into the right compartment within the system for the car to be able to generate cold with electricity; hence kept repeating ON/OFF cycle to get it functioning (with moderate success!)

However, at one unfortunate moment on the way back in beyond +30'C heat, the compressor/heat pump (read: something) failed completely and I heard some very nasty grinding sounds from their whereabouts and the car vibrated (as the system was trying to "initialize"). I did all kinds of resets (wheel, cold, etc.), but I was no longer able to get the expected sound of the compressor/heat pump to emerge, but only small "thumping sounds", after which the "Cabin climate control system requires service", Cabin heating / cooling limited or unavailable -message became predominant on the screen. I guess it's needless to say that the car warms up quite much more than what the outside air temps are during a sunny day (even with blowers at maximum); so I got to experience those +37.5'C cabin temps etc., too.


Like people have mentioned in this thread earlier, apparently the heat pump A/C related issue(s) have plagued only these early MY21 models (2020/2021).

Before my 6.000 kilometer trip, the car was serviced (under warranty) with the following:

Remote Diagnosis
General Diagnosis
Valve Body - EXV - Supermanifold (Remove & Replace)
* SERVICE KIT, SOV CORE, HEAT PUMP (1603593-00-A)
Coil - EXV - Supermanifold (Remove & Replace)
* SERVICE KIT, SM EXV COIL, HEAT PUMP (1603592-00-A)

However, the above did not fully solve the issue (some alerts had remained), which Tesla already acknowledged to me and reserved another appointment, but alas it couldn't be done before my tour in Europe.

Now, having returned back, my car got serviced by Tesla (warranty, no cost) with the following maintenance:

General Diagnosis
Supermanifold (Remove & Replace)
* SUPERMANIFOLD ASSEMBLY (1547595-A2-F)
A/C Line - Supermanifold to HVAC(Remove & Replace)
* AC LINE, ASY, MANIFOLD TO HVAC, M3 (1555055-00-D)
A/C Compressor (Remove & Replace)
* AC COMPRESSOR, 41CC (1501256-01-L)
A/C Line - Supermanifold to Compressor(Remove & Replace)
* AC LINE ASSEMBLY, SUPERMANIFOLD TO COMPRESSOR,R1234YF (1502020-00-C)

Compressor was decommissioned (per alerts), metal shavings were diagnosed in the A/C system, 
pressure release valve of compressor had released a substantial amount of oil.

Issue resolved, A/C blows cold +6'C air

Hope these help someone else! I'll post another update, if need be.

 

[Acxxu]

Update:
My issue remains in cold temperatures and is very audible: the heat pump starts to make an extremely loud noise (yes, I know they make noise, but this noise is something different) it sounds like it's trying to become a small propeller aircraft. You can also feel this as a vibration in the steering wheel while driving. In most situations, this does not become a malfunction (the sound either continues at various pitches or disappears), but tied with 80-100km/h road speeds, these seem to create the conditions where the heat pump may fail (a 'requiring service' message is then displayed on the screen and only cold air is blown from the vents). However, as it occurs, there's hope (see below for instructions how to fix/recover from the situation).


INSTRUCTIONS ON HOW TO RECOVER FROM A SITUATION WITH TESLA MODEL 3 AND MODEL Y FAILED CLIMATE CONTROL (ONLY COLD AIR BLOWING IN):

As this happens (optional):
1. Turn on the heated seats/seat warmers for all passengers (to not have them freeze as quickly)
2. Adjust the climate control speed (low) and airflow towards windows instead (you don't want the cold air to the cabin, but possibly to the windows to help them stay clear)

HOW TO RECOVER/FIX:
1. Park your car (a sheltered/warm parking hall would be preferred, but I've found this not necessary)
2. Select from Display/Screen -> Safety -> Power off
3. Wait for 3 minutes (don't move while in car so that car doesn't wake up too early, but you don't have to wait for the battery disengagement sound/click)
4. E.g. press brake pedal to wake up the car again
-> warm air comes out from the heat pump again (if you're facing the same condition as I have)

What to do if that didn't work (list of other options):
1. These days, I'd look into if there's any warm spaces nearby to take the car into. If you absolutely must continue your journey, step #2 may help, but on longer drives there's necessarily no preheating available due to distance between the chargers
2. Select from your Navigation display the closest supercharger (for preheating the battery)
- if the car will start pre-heating the battery, you may be able to continue your journey (as this should allow the octovalve to move warm air from the battery to the cabin)
3. Try selecting gear to Park and then try if Camp mode from the climate control will work (not likely to work)
4. Exit the car (find appropriate shelter, e.g. gas station) and try engaging the heating options from the Tesla App (not likely to work)


A Mini-FAQ to the above instructions:

Ok, it worked, what next?
- After the above maintenances (previous posts), I've had the above happen on me several times, latest just before New Year 2024 in Jyväskylä on the way to Lapland. The climate control has now worked for the last 2,000 kilometers after the latest malfunction (including the same aircraft take-off rotor-sounds emerging and also without them - it's as if some ice had thawed from the system. Yesterday there were just the normal operational sounds from the heat pump.)
- I can't really tell if there's damage, but as this trick works for me, I haven't taken the car into repairs for the time being. It could be that it's related to ice and melting of it, but that is just speculation from my part

My heat pump is still 'dead', why didn't these instructions help me?
- There are multiple ways of how a heating system may fail, obviously what I wrote above is for certain conditions only. E.g. this trick will not be likely to work in case your heat pump has spewed metal bits into the system (and you only hear a 'thunk' and feel a vibration a couple of times when starting the car), or it has lost too much of its coolant material for some reason

Haven't you lost confidence in Tesla after the two larger maintenance operations?
- No. At 92,400 kilometers life's been pretty good with the M3P (MY21) - read: I absolutely love it. I've driven this thing in extreme colds (-39'C and slightly colder) and in quite warm (+40'C temperatures) as my previous posts outline and yes, I have continued this 'tradition' successfully
- For me, the heat pump has been working in the 'most extreme' conditions very well, but I have seen that it experiences the most hurdles in the more moderate cold temperatures, e.g. -10..-15'C. It's as if some ice would clutter/build-up or something else disturbs the operation of the heat pump. (I've heard Tesla's road service say something in regards the frontal air inlet hatches getting stuck.)

How do you stay warm in -39'C (with failed heat pump) while driving in rural areas with poor cell coverage?
- I absolutely don't! But being prepared for such situations is important. Always have the appropriate gear with you (e.g. in warm weather extra drink with minerals, in cold weather extra gear to provide you warmth)
- Alternative heat sources: I keep a couple of sets of those "warming pads" (that skiers use, they stay warm for some 3-5 hours) and some additional clothes (you could also have a blanket or two for potential passengers too), maybe one of those small cigarette-lighter heaters (however, those I believe are too low power to save your trip), but since the Tesla does have a big battery and also a more high-powered USB-C port, maybe there are some other options available

Hope this helped someone. Safe journeys!