To be exact it was a Volta level 2 charger at 32AMps. AC and heat would drop added range to 0.
It must be defective. Were it really delivering 32 amps at 240 V the car would be getting 7.6 kW. Neither the heater nor the A/C draws that much thus there will be some left over to charge the battery if the EVSE is really delivering 7.6 kW. The cabin heater typically draws a couple of hundred watts once the cabin comes to equilibrium. The battery heater is reputedly rated 4 kW and it too would not run at its peak rating. Thus you should have a couple of kW at least left over for the battery. 1 kW puts about 3 miles per hour into an X100. Note that I am posting this from the perspective of a guy whose spends the (relative to Chicago) winter in Virginia and the summer in Quebec where we only occasionally precondition the car (if it has been sitting in the hot sun).
Just to give you an idea about the A/C: My car is charging at 239V*40A = 9.56 kW and reports that it is gaining 25 mph. If I turn the air conditioning on and turn it way down to 65 (from 80 at the start), the mileage gain plummets to 16 mph. That means that approximately (16/25)*9.56 = 6.11 kW is now going to charge the battery and the other (9.56 - 6.11) = 3.45 kW are going to the A/C. But within 5 minutes the car reports the cabin temperature at the set point and the range accumulating at 23 mpH meaning only about 650 W going to the A/C.
You need to check up how much power your car is actually drawing when preconditioning. At least look at what the display says in the car during these periods. If it reads 32A consumed and 0 mph added then take it to an SC.
The reason why i ask is because I’m between doing a Nema 14-50 which would charge at 40AMPs
It will charge at 40 A if a corded HPWC is plugged into it but those don't seem to be available any more. With the "charger" that came with the car it will only charge at 32 A.
The second less favorable option is doing a HPWC at 48AMPs if the 40AMp can’t keep up with adding range while AC and heat are running
If you are going to have an electrician out to modify the panel and pull new wire you might as well, given this, go with the hard wired HPLC and get the extra 8 amps (relative to a corded HPWC ~ 6 mph more) or 16 (relative to a 14-50R with the mobile charger ~ 12 mpH). This seems a worthwhile thing to do whether you get the Volta charger fixed or not.
...but living in Chicago both preconditioning in winter and summer is a big deal.
I think you are over doing it. It only takes the heater a few minutes to heat a really cold soaked car up to comfortable temperature. Why heat it at other times? I'm guessing that there is no need to run the battery heater under these conditions for the sake of charging as the level two charger only provides a few kW which the battery ought to be able to accept even when it is quite cold. But as I don't know any of the details I think I'll shut up and hope people with actual experience with outdoor, cold weather, level two charging experience chime in.
If the car has been sitting outside in the sun for hours it only needs about 5 minutes preconditioning to be nice and cool inside. Thus there is no reason to run the air conditioner for longer times than that.
You might want to try the mobile charger plugged into a range outlet (using the included 14-50P adapter that comes with the car) as it also allows the car to draw 32 A. If this isn't convenient at home then you could always go to a camp ground and try it there. Use an app like Stats to determine the mile accumulation rate. If everything seems OK with the mobile then that condemns the Volta unit for sure.
Glad that Tesla allows both.
