BMW i3S heat pump stopped heating

[GerryMD2024]

For 3 years, this 2019 bmw i3S 120 AH heat pump worked great. Pre-condition made car interior very warm in winter. last 2 months it stopped heating the car, but the heat pump fan works and pushes out very cold air

 

[mojo]

It will probably help to have the car's diagnostic codes read (either by someone else with a compatible code reader, or yourself with an app like BimmerLink and a compatible dongle).

I suspect that your assumption that the heat pump is at fault is incorrect. All the heat pump does (as I understand it) is to pre-heat the incoming air before the final stage of heating by the car's interior heating elements. It is ~probably~ the latter that has failed - unfortunately it's a weak component in the car.

 

[alohart]

I suspect that your assumption that the heat pump is at fault is incorrect. All the heat pump does (as I understand it) is to pre-heat the incoming air before the final stage of heating by the car's interior heating elements. It is ~probably~ the latter that has failed - unfortunately it's a weak component in the car.

Above -10 ºC/14 ºF, all cabin heat is provided by the heat pump with the electric resistance heater not operating. Below this temperature, the heat pump doesn't operate with cabin heating being provided solely by the electric resistance heater.

 

[mojo]

Above -10 ºC/14 ºF, all cabin heat is provided by the heat pump with the electric resistance heater not operating. Below this temperature, the heat pump doesn't operate with cabin heating being provided solely by the electric resistance heater.

That's interesting - something I had never read before. The ambient temperature where I live has never got down to -10 C during the whole time that I've owned the car - so that means that the electric heating in my car will never have been used? That it has been all heat pump and nothing else?

I wonder if the same rule applies during cabin pre-heating - it seems (on my car) to heat very quickly. The heating while the car is in motion, on the other hand, is not great (though that may be because my default driving mode is Eco Pro).

 

[alohart]

That's interesting - something I had never read before. The ambient temperature where I live has never got down to -10 C during the whole time that I've owned the car - so that means that the electric heating in my car will never have been used? That it has been all heat pump and nothing else?

It's all described in BMW's I01 Heating and A/C Systems Training Manual, the entire series of which is well worth downloading and reading if one really wants to understand the i3. If one assumes that the Training Manual information is correct, your cabin electric resistance heater should never have operated. Neither has mine.

When heating is active, you should hear the heat pump compressor running. If you don't hear it, that suggests that the electric resistance heater is being used.

I wonder if the same rule applies during cabin pre-heating - it seems (on my car) to heat very quickly. The heating while the car is in motion, on the other hand, is not great (though that may be because my default driving mode is Eco Pro).

I assume that cabin preheating operates exactly like regular cabin heating. Because the car isn't moving, the heat transfer fan in the opening below the front bumper should be on as well. I haven't read anything in the Training Manual that suggests otherwise.

I've selected the iDrive setting that activates Comfort mode climate control strength (i.e., full strength) when in Eco Pro mode. So if you'd like faster heating, you might consider selecting this option.

 

[SSi3]

For 3 years, this 2019 bmw i3S 120 AH heat pump worked great. Pre-condition made car interior very warm in winter. last 2 months it stopped heating the car, but the heat pump fan works and pushes out very cold air

https://www.mybmwi3.com/threads/help-no-heat.18449/

 

[weajd]

For 3 years, this 2019 bmw i3S 120 AH heat pump worked great. Pre-condition made car interior very warm in winter. last 2 months it stopped heating the car, but the heat pump fan works and pushes out very cold air

The AC Compressor [EKK] provides the heat to the heat exchanger up front. Is your AC compressor working right or sounds like it is not?
If not, this can be an expensive repair.
The BEV with the heat pump (REX does not have heat pump) also has the electric heater up front that should complement the heat exchanger when needed in freezing temps. If the AC compressor has failed, I would assume the electric heater would take over.
I have been wondering if the BEVs with heat pumps are more prone to AC compressor failure if they are used to both cool the passengers/battery as well as heat the passengers.

One more point - as I recall, a fuse in the EME has both the electric heater and AC compressor tied to it so if either one uses too much current, the fuse blows. If this happens, BMW replaces the EME and does not repair it.