Spurious operation of E-Heat

[Rex]

I turn off E-Heat and the power to A/C. It randomly turns itself back on with no intervention from me. I only notice because the Auto light comes back on. I have also had seat heating and steering wheel heating do "Their Own Thing"
Has anyone else experienced this?

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[tfitzgex]

I have, mine is even a bit weirder. I pull up to my mailboxes, put my car in pork. Open my door. get my mail sit down in my car, the heat comes on HI (even if it was off) We have gremlins.

 

[likescookies]

I've never had the seat or steering wheel heat come on by itself, but the behavior of the HVAC system is a mystery to me and I never know whether or for how long it will stick when I shut off the AC and EHeat. I wish HVAC had physical controls rather than running through the screen UI.

 

[JeffGo]

I have only had the seat & steering wheel heating come on once with no explanation. Well, I was playing with the remote start that one time. E-heat seems to always be set to on or keeps setting itself on. This time of the year, I'm going to leave that alone.

 

[Rex]

I've never had the seat or steering wheel heat come on by itself, but the behavior of the HVAC system is a mystery to me and I never know whether or for how long it will stick when I shut off the AC and EHeat. I wish HVAC had physical controls rather than running through the screen UI.

I wouldn't mind the software switches if they did what they were told.

 

[Mach-Lee]

I have, mine is even a bit weirder. I pull up to my mailboxes, put my car in pork. Open my door. get my mail sit down in my car, the heat comes on HI (even if it was off) We have gremlins.

The HVAC system turns on E-heat in response to temperature and humidity changes. So yes if you open the door that would cause a large temperature and humidity shift inside the car which could cause HVAC system changes. Not sure if this is a bug or not, could be as designed. Should try rolling down the windows without getting out of the car and see if it's the same behavior.

High humidity will trigger E-heat to provide dehumidification to the cabin FYI. Many people aren't aware that humidity alone can trigger a change even when the temperature remains constant. If you bring wet objects or people in the car it will react to this.

I wouldn't mind the software switches if they did what they were told.

It's coming on because you're in defogger mode. E-heat is mandatory in defogger. If you want to turn E-heat off, select a mode other than defog.

I strongly recommend folks just use the AUTO option all the time and simply adjust the temp up or down until they're comfortable, this is how it was meant to be used by most people. AUTO will keep some warm air blowing on the windscreen in cold weather to prevent frosting.

 

[Rex]

The HVAC system turns on E-heat in response to temperature and humidity changes. So yes if you open the door that would cause a large temperature and humidity shift inside the car which could cause HVAC system changes. Not sure if this is a bug or not, could be as designed. Should try rolling down the windows without getting out of the car and see if it's the same behavior.

High humidity will trigger E-heat to provide dehumidification to the cabin FYI. Many people aren't aware that humidity alone can trigger a change even when the temperature remains constant. If you bring wet objects or people in the car it will react to this.



It's coming on because you're in defogger mode. E-heat is mandatory in defogger. If you want to turn E-heat off, select a mode other than defog.

I strongly recommend folks just use the AUTO option all the time and simply adjust the temp up or down until they're comfortable, this is how it was meant to be used by most people. AUTO will keep some warm air blowing on the windscreen in cold weather to prevent frosting.

Thanks for that. Interestingly the Ford experts have failed to communicate that. I cannot recall the exact circumstances now but don't recollect deliberately turning on defog. I think my wife was operating the controls and hit the wrong button.
Also one might expect the software to warn you when attempting to turn off E-Heat when in defog mode.

 

[SteveUk]

Eheat

I turn off E-Heat and the power to A/C. It randomly turns itself back on with no intervention from me. I only notice because the Auto light comes back on. I have also had seat heating and steering wheel heating do "Their Own Thing"
Has anyone else experienced this?

if on manual fan operation eheat will turn itself back on it you have the blowers pointing to the window screen only.

if you have the system set to AUTO then I believe Eheat will also toggle back on if necessary. but I haven't tested that.

 

[WildfireOne]

Personally, this vehicle's HVAC behavior is infuriating and my #1 complaint on this car, mainly because while I might use PAAK once in a week, I will adjust hvac every single time I'm in the car.

Just try toggling the AC within the first 30 seconds to minute of starting the vehicle (without AUTO fan toggled on, and no vent locations selected). It will toggle and then revert. And keep reverting until the UI is fully booted (about 1 minute) -- utterly frustrating. The workaround is to have a vent location (like dashboards or floor or windshield) already selected before power off. No other vehicle I've ever had does this crap.

And the eHeat comes on by itself. Really, that's WTF territory since everyone knows that the resistive heater is one of the biggest battery hogs in an EV. Here I am trying to maximize my efficiency and range this effin' eHeat comes on by itself, even when I've finally allowed myself a little AC... Yup, eHeat comes on with AC on. Outside of people in a literal fog, who the hell drives with BOTH the AC and heater going..?

I think it's really asinine, idiosyncratic HVAC behavior allowed by @Ford Motor Company.
I've had Mazda, BMW, Nissan, Lexus, Subaru, Audi, VW, Chevy, and Mercedes vehicles and none of them do any of this crap. If the HVAC setting AUTO is off, the user should have full manual control. PERIOD.

 

[Jimrpa]

I have, mine is even a bit weirder. I pull up to my mailboxes, put my car in pork. Open my door. get my mail sit down in my car, the heat comes on HI (even if it was off) We have gremlins.

Your car fits in pork? That must be a very large pig ?

back on topic, I’ve noticed that E-heat does sometimes turn on when not expected (when it’s warm out and only AC is required). If I happen to go into the climate control screen and catch it, I turn it off. I wonder what the strategy is for turning on E-heat?

 

[Lord Polymath]

Your car fits in pork? That must be a very large pig ?

back on topic, I’ve noticed that E-heat does sometimes turn on when not expected (when it’s warm out and only AC is required). If I happen to go into the climate control screen and catch it, I turn it off. I wonder what the strategy is for turning on E-heat?

I was going to ask what kind of BBQ sauce he likes

 

[srogers]

I have the same issue. If my car has been turned off for about an hour the AC or E-heat will randomly turn on; it doesn’t matter if the system is in auto or manual.

 

[breeves002]

And the eHeat comes on by itself. Really, that's WTF territory since everyone knows that the resistive heater is one of the biggest battery hogs in an EV. Here I am trying to maximize my efficiency and range this effin' eHeat comes on by itself, even when I've finally allowed myself a little AC... Yup, eHeat comes on with AC on. Outside of people in a literal fog, who the hell drives with BOTH the AC and heater going..?

Firstly they give the user full manual control. They just revert when the HVAC believes it needs to. This is to avoid issues with most normal people that will buy this car..as well as stupid people that don't understand HVAC operation. If you turn the e heat off then forget about it and it never turns back on automatically, you may have issues with the windshield fogging. This is more of a safety feature and feature for most drivers that aren't like you that just drive the car.

AC lowers humidity. Keep in mind this is a variable AC compressor so just because the AC is "on" doesn't mean it is drawing 5kW. The AC in general is a very low draw except when trying to cool a very hot cabin. Once it is cool it takes almost negligible amounts of energy. This is all standard HVAC programming. As far as I know all vehicles with auto HVAC will turn the AC on and heat to max if you put it in "max defrost". Defrost works best with high heat and AC running. With the AC off it is much harder to defrost due to high humidity.

In the end, unless you need every last tiny bit of range just leave it in auto mode as @Mach-Lee suggested and then manually turn the e-heat off if you want to. Just because the 'e-heat' is on doesn't actually mean it's sitting there running full blast either. Even if it is running at the full 5kW constantly, that's roughly 5-6% of your battery in an hour of driving. Where I am that's 50-60 cents worth of electricity. The AC running to help defrost likely uses 500W or less. About one half of one percent of your battery in 1 hour. These #'s assuming ER pack. Would be 20% higher for SR.

In the end stop worrying about it. You have a huge battery, it's not a 23kWh Focus Electric where 1 hour of full blast heat takes 25% of your battery!

 

[ncaadam]

fwiw - the manual does specifically say that e-heat cannot be turned off in certain modes…​

 

[RickMachE]

#FirstWorldProblems

Also, the use of the word "spurious" in the title is puzzling.

not genuine, authentic, or true; not from the claimed, pretended, or proper source; counterfeit

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