2018 Model 3 with Intermittent no heat

[Michael A]

I have a 2018 Model 3 with 54k miles, all of a sudden yesterday the heat doesn't seem to work anymore. I rebooted the MCU multiple times and after sitting for about an hour the heat started working again. This morning heating was working, just now out to lunch heat isn't working again.

I usually have the HVAC set to auto 70 degrees. I changed it to manual and moved the temp to HI and still nothing.

With the NO HEAT condition I don't see a spike in energy consumption like I normally do when the heat is working.

I searched around and it seems a few people had indicated a temp or humidity sensor inside the the cabin might be bad?

Any insight? Does Tesla still have mobil techs that can repair this?

 

[Michael A]

Very odd, so after rebooting the MCU AND letting the car sit parked for an hour the heat now works again.
Has anyone seen this behavior before?

 

[Michael A]

So Tesla service advised me to update to the latest version which I did last week and perhaps is what is now causing the issue, not sure.
Additionally they asked me to exit the vehicle, close the door so the center display turns off. Re-enter the vehicle turn HVAC ON then OFF several times, then set to AUTO. This may have worked.
I updated to the latest version on Wednesday and the next day is when the problem started, I cannot believe I am the only one experiencing the issue.

 

[Leonard4]

So Tesla service advised me to update to the latest version which I did last week and perhaps is what is now causing the issue, not sure.
Additionally they asked me to exit the vehicle, close the door so the center display turns off. Re-enter the vehicle turn HVAC ON then OFF several times, then set to AUTO. This may have worked.
I updated to the latest version on Wednesday and the next day is when the problem started, I cannot believe I am the only one experiencing the issue.

I had a similar issue where Tesla actually replaced the PTC Heater in my Model 3, I'm seeing the same issues after the replacement was installed so I'm opening another service ticket today. It definitely feels like this v11 update might be involved, things ran pretty good before then, but now it just all seems clunky.

 

[Michael A]

What is a "PTC Heater" ? Is it a simple sensor or the main heating unit ? Just wondering because I am out of warranty.

 

[Gyrolion]

It is the main heating unit that warms the air up.

 

[Michael A]

Looks like Tesla will be replacing the PTC heater, $750.

 

[Michael A]

HMMM ... apparently I am not the only owner with a resistive PTC heater that failed after last weeks update.
Just seems odd, 54k miles not ONE problem. 24hrs after the latest update, heater fails.

Older Tesla Model 3s without heat pumps also experiencing heater failures

The heating problems don't appear to be limited to just heat pumps, as the resistive heating system in older Model 3s has also been failing.

driveteslacanada.ca

 

[al503]

12/18 production 3P (2021.44.30): I had a similar issue last weekend. I usually set the temp at 70 (manual setting), which is comfortable for me. I noticed that it seemed like it was blowing noticeably colder air and I bumped it up a couple/few degrees, eventually reaching HI. It was putting out some heat but it still felt like it was less than what 70 normally puts out...

So, for me, there wasn't a total loss of heat. and things seem to be normal again on subsequent drives so far....

 

[Michael A]

Mine was intermittent for the first few days, it would work after being parked for 1hr, then 45 min then 30. Finally no heat at all. Tesla service advised me to to turn the heating system on and off a few times manually then press auto. It didn't work. Car has been a Tesla since Tuesday as they are awaiting arrival of the PTC heater part.

 

[STS-134]

What is a "PTC Heater" ? Is it a simple sensor or the main heating unit ? Just wondering because I am out of warranty.

Positive Temperature Coefficient -- a type of heater that essentially can self regulate its temperature by drawing more current when it's colder and less current when it gets hot. It's an electric resistance heater and what the Model 3 used for heating prior to the heat pump being introduced.

 

[mat1990dj]

I’ve got a model 3 that I’ve let to my father while I’m 8 months away and I’m starting to get worried. I just found a super interesting set of videos on YouTube…. TL;DR: the heater runs
always, even in summer!

https://youtube.com/channel/UCBcMfFZgtLTmvhTo-5I5NfA

 

[M109Rider]

I had that happen to mine just last week.
Started a little while before v11 though.
Intermittent heat just like you guys describe above.
Set an appointment to have it checked at the service centre.
Only mine started working again about a week before the service appointment.
So it went in, but didn’t get replaced. They recommended it get replaced, but I held off just in case it was software, or just some glitch. (Kind of new it wasn’t) but hey, don’t fix what isn’t broken right.
Well, about 2 or 3 weeks later, I’m sitting in my car parked with the heater on. Suddenly I hear a clunk.
Then moments later the screen flashes a few different messages basically saying vehicle may not start, electrical system won’t support all features.

So what happened (after getting my car towed to a service centre) was the PTC heater I guess finally gave out. Caused a dead short this time though. (I was told) which forced the computer to disconnect from the main high voltage battery pack to avoid further potential problems.
Long story short, heater has now been replaced, all is right with the world again.

Morale of the story, if your PtC heater is acting up, know that one outcome could be a short, resulting in a shut down and tow to the service centre. Choose wisely how you wait it out, just in case it dead shorts.
Don’t recommend choosing my way.

 

[MCBalay]

I started another thread this morning before I found this one.
Still not clear on which software version "seems" to have triggered issues in PTC Heater M3 (early builds)

Software Fix? to Heat Pump * Non-Heat Pump Model 3? Software Version?

I have a 2018 M3 (non-heat pump) but following all things Tesla I have been watching the journey of people in super cold climates (I am in moderate PA) with complete failures of the heating system. I saw a twitter post (sorry. didn't catch the specifics) that indicated Tesla was pushing a "fix...

teslamotorsclub.com

 

[Michael A]

I am in NY, purchased the car about a month ago from the original owner who lived in Northern Michigan very close to the Canadian border so I would assume the older resistive heating system has had greater use over its life because of its colder climate. Perhaps mine and other Model 3's in colder climates have had more usage or hours and this update (2021.44.30.7) from last week put the heating system out of its misery.

I have asked Tesla service to consider covering the cost because I am only a few thousand miles over the standard warranty and I really feel like the cause of the failure was directly related to the update.

So far they have agreed to not charge me for "reseal front upper control arm and ball joints", "Inspect X950 and X952 for damaged electrical circuits" and "replace charge port electrical pin deadfronts". Originally these 3 items where another $150-$200.

So my pending charge is $550 for PTC heater plus $195 for installation. $745 plus tax total.

They did give me a loaner until the PTC heater comes in so I kinda feel like in this day and age a rental car would have cost me $500 for the week if I could even find one.

 

[M109Rider]

I am in NY, purchased the car about a month ago from the original owner who lived in Northern Michigan very close to the Canadian border so I would assume the older resistive heating system has had greater use over its life because of its colder climate. Perhaps mine and other Model 3's in colder climates have had more usage or hours and this update (2021.44.30.7) from last week put the heating system out of its misery.

I have asked Tesla service to consider covering the cost because I am only a few thousand miles over the standard warranty and I really feel like the cause of the failure was directly related to the update.

So far they have agreed to not charge me for "reseal front upper control arm and ball joints", "Inspect X950 and X952 for damaged electrical circuits" and "replace charge port electrical pin deadfronts". Originally these 3 items where another $150-$200.

So my pending charge is $550 for PTC heater plus $195 for installation. $745 plus tax total.

They did give me a loaner until the PTC heater comes in so I kinda feel like in this day and age a rental car would have cost me $500 for the week if I could even find one.

What’s the X950 and X952 inspection. ?

 

[Michael A]

What’s the X950 and X952 inspection. ?

https://static.nhtsa.gov/odi/tsbs/2020/MC-10184229-9999.pdf

 

[Hithisisjenn]

New to the no heat party. Any quick fixes?

 

[EVJAutoJunkie]

I had the same problem a couple days ago. It happened during a deep freeze. I am guessing your windshield and rear windows heaters turn on, the steering wheel and seats turn on as well, but the main vents do not. You may also not be able to trigger climate control from your app where it will intermittently tell you Climate On Failed. Lastly, you may also find there are times where it will work all the sudden, but then stop. You are not alone as there is a super long thread in the Canada forum for this exact same issue.

My car is in the shop and they need to replace the Supermanifold and Compressor. I would guess they may need the same for you, but they'll tell you they are short of parts and you'll have to leave it there.

That said, you need to bring it to the shop asap. Don't wait for any mobile service or future schedule. Drive it into the shop and ask them to take care of it asap as this is a major safety issue. They can't afford to have you wait to come another day while you drive your car in dangerous freezing temperatures.

Good luck!

 

[Hithisisjenn]

This is ridiculous…: Someone is going to freeze to death and die