E-Heat ... always on ???

[Deleted member 3569]

I live in central FL and daily temps hardly drops below 75ºF around most of the year ... but during early part of day the E-Heat kicks in. I notice this when my efficiency drops below 2.8 mi/kWh and as soon as I shut it off it goes way upwards of 3.3 mi/kWh. This also happens when outside temp starts to drop from 90º+F down to 80ºF. If I manually shut it off it stays off till next start. I use Auto feature either set to lowest dot or middle dot and in this configuration my A/C is always on . It is comfortable inside the cabin and the temp seemed to be what I have set ... is this normal? Or is this purposely done to dehumidify the cabin air?

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[mpshizzle]

It will automatically turn itself on occasionally, because it uses that to heat the battery. But just the button being turned on doesn't necessarily mean the heater is running. It just means it CAN run if needed

 

[Logal727]

It will automatically turn itself on occasionally, because it uses that to heat the battery. But just the button being turned on doesn't necessarily mean the heater is running. It just means it CAN run if needed

Yeah it’s pretty confusing, it kind of explains it in the manual

 

[Jimbo]

This is my fourth biggest gripe with the car, that it decides to randomly turn on e-heat or AC as it sees fit, not as I tell it.

When it's 65 in the morning, and I have a five minute drive, no, you don't need to waste energy heating my cabin to 70, I'm perfectly comfortable. Really wish the HVAC would stop pulling a HAL, or at least had some temperature hysteresis.

 

[Deleted member 3569]

It will automatically turn itself on occasionally, because it uses that to heat the battery. But just the button being turned on doesn't necessarily mean the heater is running. It just means it CAN run if needed

I don't agree ... to pre heat the HVB in FL weather? I am not talking about arctic temperature conditions. The cooling fan will come on automatically during either L2 or dcFC charging to cool the HVB, that is done independently from cabin HVAC system. I know the E-heat is activated because I can see my efficiency drop... but the air is still cool coming out of the vents. The most logical explanation that comes to my mind is to dehumidify the cabin environment but I do not know if there is a humidity sensor in the Mach-e HVAC.

 

[Motomax]

I don't agree with this logic ... if heat is needed for the HVB then it should be activated independently and not be part of the cabin HVAC. My 2012 Lexus ct200H has a similar cooling fan for its hybrid battery and it comes on its own accord.

You’re right, you can’t control the battery conditioning. It will do it’s own thing no matter what.
it’s possible it’s humidity related but even that you can’t turn off. I think it’s just crappy configuration for the hvac. I’ve seen it do some weird things to the point where I’ve gotten in the habit of turning off what I don’t want (ac or heat) every ride.

 

[Kamuelaflyer]

the button being turned on doesn't necessarily mean the heater is running. It just means it CAN run if needed

A better nomenclature for that would be “e-heat Armed. I think that would be less confusing. Or not.

 

[connoisseurr]

I will say the benefit of a 2022 (for now) is recirculate actually stays on

 

[Deleted member 3569]

I will say the benefit of a 2022 (for now) is recirculate stays on

The re-circulation mode works fine for me, I noticed that in extreme hot condition it is activated ... I don't know this is true if in subfreezing temperatures. On my Lexus it is auto activated in very hot or very cold conditions.

 

[Deleted member 3569]

Yeah it’s pretty confusing, it kind of explains it in the manual

In the Owner's Manual emphasis is made not to engage e-Heat but to use heated seat at all times possible in order to maximize efficiency... so the actual system operation contradicts the Owner's Manual perspective.

 

[Maquis]

Mine seems to develop a memory. When it started warming up last month, I turned E-Heat off every time I started the car. After a while, it stopped defaulting to ‘on’ every time I started the car. As the weather heated up, I had to manually turn on the A/C several times at startup. Now it’s on by default.

 

[Deleted member 3569]

Mine seems to develop a memory. When it started warming up last month, I turned E-Heat off every time I started the car. After a while, it stopped defaulting to ‘on’ every time I started the car. As the weather heated up, I had to manually turn on the A/C several times at startup. Now it’s on by default.

This is so far the best answer I heard so far .... thank you for sharing !!!
The best HVAC system of any cars that I have ever owned is my 2012 Lexus ct200H ... when you first start the engine cold, the HVAC doesn't do anything for at least a minute then it either starts the A/C or the heat or both if the temperature is around 69ºF ... it "thinks" for a minute or so before doing any thing stupid to annoy the driver !!!

 

[JohnFoxeSheets]

Yeah it’s pretty confusing, it kind of explains it in the manual

This is what I found in the 2022 manual. Doesn't seem to explain that E-Heat means it could heat, but it isn't necessarily actually heating... Am I missing something?

 

[JohnFoxeSheets]

I will say the benefit of a 2022 (for now) is recirculate actually stays on

Not on mine it doesn't!

 

[Deleted member 3569]

This is what I found in the 2022 manual. Doesn't seem to explain that E-Heat means it could heat, but it isn't necessarily actually heating... Am I missing something?

Written typically by a computer genius ... it contradicts every sentence.