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Cabin heating indicator?

Thu Sep 22, 2016 6:08 am


We're starting to get cool mornings while the afternoons are pretty hot, +90F/+32C. So I'll set the AC temperature to 78F/25C and life is good on the way home. But the next morning when it is cool 68F/20C, I got the impression I was getting cabin heat out the vent as I had not changed the temperature setting.

Did I by accident run the cabin heater?

For now, I see that AC has a light indicating it is working. I've not seen a heater working light. Did I miss the memo?

Bob Wilson
20k/27k mi 2014 BMW i3-REx
10k/10k mi 2017 Prius Prime

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Re: Cabin heating indicator?

Thu Sep 22, 2016 6:15 am

I thought it was all controlled by the same system?

So if you set the temp to 25c, that's what the car will try to achieve by referencing the current outside temperature. I think there's a bit of a flaw in the implementation logic here.

When it's hot outside in the day / evening, you may want air con on but like many, it's tempting to leave the temp setting relatively high to stop excessive AC cooling and battery drain. Trouble is, if you leave it like that, in the morning when the temperature outside has fallen to 10c then the pre-conditioning is going to whack the heating on to try to achieve 25c internally.

Or have I missed something?

I think you have to consider what temperature you want the car to pre-condition to and make sure you set that before switching off for the night.

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Re: Cabin heating indicator?

Thu Sep 22, 2016 9:59 am

Our cars don't have a switch to control the heater. The only way to ensure that the heater is off is to drive in the Eco Pro+ mode. Maybe setting the cabin temperature to the minimum will also work.

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Re: Cabin heating indicator?

Thu Sep 22, 2016 10:22 am

The car will use whatever is required (heating or cooling) to get the cabin to the setting you configure.

Keep in mind that should you decide to drive with the windows open, BMW has said that if you drive over 25mph, it takes more energy because of drag verses just letting the car do it with the HVAC system.
Jim DeBruycker
2011 535i x-drive GT, 2014 i3 BEV

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Re: Cabin heating indicator?

Thu Sep 22, 2016 10:35 am

FWIW A/C does not always mean cold air. It helps get rid of humidity.
2015 i3 rEX Arravani Grey giga, parking, tech, 20"

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Re: Cabin heating indicator?

Sat Sep 24, 2016 12:02 am

The i3 like all modern BMWs has automatic climate control, not the simpler manual systems found in less expensive makes. I've found it works best if you set your desired temperature and program intensity then let the computer do its thing. In Comfort, it's every bit equal to my 3-series in terms of heating or cooling the cabin rapidly. Switching to EcoPro definitely reduces how quickly the system reacts. I find the cabin gets a bit stuffy, particularly on sunny afternoons. EcoPro+ shuts off all heating/cooling as others noted previously. I think the fan will still bring in air but I'm not sure since I rarely bother with that mode.

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