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Do Winter Heater Failures Portend Summer A/C Failures?

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JHCCAZ

Electrified Engineer
Supporting Member
Feb 2, 2021
1,638
3,922
Tucson
As an imminent MY customer, I've been paying attention to the various threads about Heat pump problems. At the moment these are mostly stories of inoperative cabin heating/defrosting in extreme winter conditions. However, there are also older threads floating around about weak or occasionally failed A/C.

It hasn't been very clear whether the new HVAC system design is inadequate (with or without extra tinting of the roof and windows which I'd be very willing to do), or whether some of those reports were indicators of partially failing Heat Pump systems.

All sympathies to those who are struggling with serious issues in the Frozen Northlands. But here in Southern Arizona the problem would be failure to keep up with intense sun and summer heat. Even right now, A/C is needed during the day though not intensively so. Pretty soon now, a weak A/C would become a real summer bummer.

The intrinsic nature of the Heat Pump HVAC might suggest that, if indeed there are some faulty components responsible for the heater/defroster nightmares now, we might expect further troubles with A/C this summer.

I'd be interested to hear from anyone who thinks they understand the situation more clearly.
 
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dont worry -- I picked up my car in July while people were complaining about AC failures - yet - through the entire summer it worked flawlessly. Same for winter. There have been problems - they have fixes. Extreme issues require the new 'octovalve'.... I wouldn't worry about it -- for everyone that comes on here and complains - and the complaints are real - there are thousands of owners that have no issue. Remember - people that frequent these boards are in the very small minority...
 
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Well, my heat failed last week on my June built MYP.
I made an SC inquiry in the app and the soonest I can bring it in is 6 weeks from now.
It sure sucks driving with my head out the window in 28-degree weather as the windows are fogged up and the snow, ice here in NJ has been more than in previous years.

Tesla offered me Uber credits as they have no loaners but I can't fit 2 baby seats in an Uber during COVID so this will be a real challenge.
I'm sure they will figure it out quickly as I think mine needs a new AC Compressor and 2 pressure switches.

I noticed a few weeks ago the heat was going out here and there and then all of a sudden I see the HVAC Fault message near the Dog Mode menu with no other faults.
 
They said they can’t even take it in any sooner as they don’t even has any place to park them since this has been going on.

they said if they did have space it would just sit anyway as they have to wait h til parts can get caught up on all the orders.

I could take it to Cherry Hill SC but that is very far and that’s a week out and I’d have no way to get back home from that far or even drive it there with no heat and fogged up Windows.

I will try again tomorrow to see if Springfield or Paramus can try to take it in sooner. NJ seems to have a lot of these failures I’m told
 
Iceman....... I would be all over that service center to get this fixed quicker than six weeks.

Unless - the really proper fix requires parts, like the oft-mentioned pressure switches (some say electrically-driven compressor), that are having reliability issues with better replacements not yet available.

I fully admit that I'm extrapolating here, but there is some evidence that the known problematic components are still going into new cars. Presumably Tesla would be switching over to a better source as soon as it's available in quantity. If all that is true, then one has to weigh the necessity/benefit of an immediate fix using current parts, against a later fix with improved parts.

Yes, I know this is pretty speculative and I completely recognize how far it could differ from the real explanation. But it's just possible that the six-week delay has to do with an internal timeline for availability of a better solution.
 
So many unknowns. Is Tesla stalling as they (diligently?) re-engineer the system? Is the supplier of the octovalve/sensor/parts having QC issues? Is the 6 week delay caused by understaffed Service Centers?
 
Hard to tell the reason exactly but, the SC emails I’ve seen say :

parts on order , AC Compressor, part # 1501256-00-I.

Please note: Parts required for your service that are available on site at our service center will not be listed here.
 
Well, my heat failed last week on my June built MYP.
I made an SC inquiry in the app and the soonest I can bring it in is 6 weeks from now.
It sure sucks driving with my head out the window in 28-degree weather as the windows are fogged up and the snow, ice here in NJ has been more than in previous years.

Tesla offered me Uber credits as they have no loaners but I can't fit 2 baby seats in an Uber during COVID so this will be a real challenge.
I'm sure they will figure it out quickly as I think mine needs a new AC Compressor and 2 pressure switches.

I noticed a few weeks ago the heat was going out here and there and then all of a sudden I see the HVAC Fault message near the Dog Mode menu with no other faults.
I would Second Boston Car Guy. Since Tesla's use software to control lots more than a conventional vehicle, it is worth mucking around with settings to see if somehow that fixes things for now. Heck, even changing your steering settings might fix it!
 
As new Model Y owner experiencing heat failure after owning the car for two-days and 180 miles the issue is real and is still occurring in new builds. Sales advisor said it is common on Model Y and new Model 3s. He used terminology of “sporadic but common.”

To your question, the two-days we had the car it did seem that the vehicle was not heating properly. My wife was having a hard time get the temperature to remain consistent. On her 1/2 hour drive home from work she would set the temperature at 70 and it never got above mid 60’s the entire time. My Model 3 would get to temp within minutes and had no issue maintaining the temp.

My point is, it appears that difficultly maintaining temperature (hot or cold) may be a precursor to the failure. I would look for this sign if concerned.
 
As the person who first encountered this problem in my 2020 MYP which was built on day 1, I can tell you that if one fails then the other will fail. The reason is that the MY uses a heat pump, and the action of heating and cooling is the same, simply the reversing of a valve. I had some days where it was 105 outside and 103 in the car. in the winter I did a 3 hour drive at 42deg inside the car. Tesla had to buy the car back and give me a new one because the failed heat pump damages the batteries and motors due to its inability to condition them. The new MY is working fine so far in both heating and AC cranked, but the warmest it has been is 68 outside when I cranked it up. We will see.
 
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Sort of afraid to comment in case I jinx myself but...
late June 2020 delivery, VIN 9xxx
Use the A/C in summer, sometimes for 8+ hours at a time using dog mode.
Now in winter, use it to warm up the car before leaving and while traveling.
No issues with heating or cooling. *knock on wood*
I have been using Auto mode.
 
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Hard to tell the reason exactly but, the SC emails I’ve seen say :

parts on order , AC Compressor, part # 1501256-00-I.

Please note: Parts required for your service that are available on site at our service center will not be listed here.
I"m sorry to hear this. Maybe picking up something like this can help raise the temperature in the car enough to at least alleviate the fogging! And you can use when camping at other times.

Lasko My Heat Heater: https://www.amazon.com/gp/product/B003XDTWN2
 
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