Heating problem

[Sara4711]

I took delivery of a MG4 Trophy model in Sweden the 29th of december and have been pretty happy with it so far even if I had some annoying little problems with it. So far I have had the car parked in a garage with a temperature of about 14 degrees celsius. The 8th of March I moved to a new apartment where I lack a garage and have to park on the street. The night between the 8th and 9th of March we had about -12 degrees celsius. I had a service appointment booked to fix some of the annoyances so in preparation fot this I ran 2 remote HVAC sessions before coming to the car. When I arrived at the car it was frozen and the windscreen was totally fogged up. I rased the temperature to 30 degrees and arrived at the service station about 20 minutes later with the temperature in the cabin at about -2 degrees.

I had a previous service appointment where they topped up the fluids in the HVAC which obviously for many cars was not correct from the factory.

When I collected the car they told me that only yesterday, the 7th of March, they got the information that some MG4´s have an error that prevents the heating from working correctly. The are awaiting to get some fix from MG that they will test on some of there own cars before installing in an customer cars. However as an interim solution I can get the heating to work, kind of, if I disable the auto mode.

They upgraded my car to R33 software version during the service visit.

Is there any other with the same type of problems?

 

[Mr Savage]

Many reviews have reported they need to set the temperature to 26 degrees or more to get the right amount of heating during winter.

 

[Eber]

In fact, there seem to be two separate problems with the heater.

1.) In some cars the cabin temperature sensor does not work properly. You can check this by reading the interior temperature with the iSMART app. In those cars the temperature has to be set much higher than desired to get some heat out of it.

2.) Sometimes, especially after unplugging from charging the car, the HVAC system does not work at all. Regardless of the settings it does not heat up. There are multiple reports of this and according to the German forum dealers are aware but MG doesn't offer a solution yet.

 

[tsedge]

In fact, there seem to be two separate problems with the heater.

1.) In some cars the cabin temperature sensor does not work properly. You can check this by reading the interior temperature with the iSMART app. In those cars the temperature has to be set much higher than desired to get some heat out of it.

2.) Sometimes, especially after unplugging from charging the car, the HVAC system does not work at all. Regardless of the settings it does not heat up. There are multiple reports of this and according to the German forum dealers are aware but MG doesn't offer a solution yet.

Yes, I have heard of both of these. In my car (built end Nov 2022) the temperature sensor seems fine, and I have yet to experience the second problem, however where I live it never gets below 0C so maybe this is related to lower temperatures?

 

[Eber]

I had issue 2.) a couple of times, always after charging. The HVAC just doesn't start up, no relation to the outside temperature.

 

[Sara4711]

I have had numer 1 before and that can as Said be rectified by sertinh the temperature higher. Hower my current problem sounds similar to number 2 even if it was not related to loading the car, running in manual worked on mine.

The dealer should call me back when they got the solution from MG am tested on some of their cars first.

A fun fact about the app in my iPhone is that sometimes when it scans my car it reports the inside temperature as 87 degrees centigrade even when it actually is below freezing. ?

 

[siteguru]

I had issue 2.) a couple of times, always after charging. The HVAC just doesn't start up, no relation to the outside temperature.

That'll be the plugged in not charging issue. I get that too. As regards heating ... I normally set AC to 23°C auto fan and that keeps the cabin warm enough for me. For preheat I set the temperature to 32°C (via the app) so that it gets very toasty to defrost the windows.

 

[Eber]

That'll be the plugged in not charging issue. I get that too. As regards heating ... I normally set AC to 23°C auto fan and that keeps the cabin warm enough for me. For preheat I set the temperature to 32°C (via the app) so that it gets very toasty to defrost the windows.

No. I unlock and unplug the car and THEN the HAVC system does not start up.

That the car can't be preheated when plugged in is yet another issue.

When your car gets warm inside when set to 23°C then it obviously does not have the cabin sensor issue. Mine has. (See below ;-) ).

 

[Buster72]

I took delivery of a MG4 Trophy model in Sweden the 29th of december and have been pretty happy with it so far even if I had some annoying little problems with it. So far I have had the car parked in a garage with a temperature of about 14 degrees celsius. The 8th of March I moved to a new apartment where I lack a garage and have to park on the street. The night between the 8th and 9th of March we had about -12 degrees celsius. I had a service appointment booked to fix some of the annoyances so in preparation fot this I ran 2 remote HVAC sessions before coming to the car. When I arrived at the car it was frozen and the windscreen was totally fogged up. I rased the temperature to 30 degrees and arrived at the service station about 20 minutes later with the temperature in the cabin at about -2 degrees.

I had a previous service appointment where they topped up the fluids in the HVAC which obviously for many cars was not correct from the factory.

When I collected the car they told me that only yesterday, the 7th of March, they got the information that some MG4´s have an error that prevents the heating from working correctly. The are awaiting to get some fix from MG that they will test on some of there own cars before installing in an customer cars. However as an interim solution I can get the heating to work, kind of, if I disable the auto mode.

They upgraded my car to R33 software version during the service visit.

Is there any other with the same type of problems?

Does yours not have a heat pump?

 

[tsedge]

I have had numer 1 before and that can as Said be rectified by sertinh the temperature higher. Hower my current problem sounds similar to number 2 even if it was not related to loading the car, running in manual worked on mine.

The dealer should call me back when they got the solution from MG am tested on some of their cars first.

A fun fact about the app in my iPhone is that sometimes when it scans my car it reports the inside temperature as 87 degrees centigrade even when it actually is below freezing. ?

Fantastic, so you have the Sauna edition then? ?

 

[siteguru]

Ah. That's what SE stands for.

 

[Sara4711]

Does yours not have a heat pump?

Yes it does but still the problem mentioned in this post.

That'll be the plugged in not charging issue. I get that too. As regards heating ... I normally set AC to 23°C auto fan and that keeps the cabin warm enough for me. For preheat I set the temperature to 32°C (via the app) so that it gets very toasty to defrost the windows.

Where do you do that, i can only se the choice to start HVAC from the app and that does not give me the possibility to set the temperature.

Found it, it was not the most intuitive place in the app.

 

[siteguru]

Yeah - you only find the temperature option once you've started the preheating function.

 

[hubj540]

Same issues as Sara4711.
Also a MG4 Trophy LR, with heat pump.
Delivered in Feb 2023.
Have to set it to 27 in order to get any heating in the cabin.
So I definitely have the faulty temperature sensor.

But I also experienced twice that the heating isn’t working at all.
Both times it was solved by parking the car, exit and lock it.
Then when entering the car again, everything went back to normal.

This is not good at all.
During winter, I have a pretty iced car after 2 x 10 minutes preheating set on high.
On the same parkway we have our MG5 facelift LR that doesn’t have the heat pump. And that car is warm and have totally de-iced after 10 minutes of preheating!

So, as it doesn’t get particularly warm, sometimes fail to produce heat at all, and has to be set to +27 when it does work, and is extremely noisy when set to Auto, this car is not built for the climate we get during winter here in Scandinavia.

Apart from that, I love the MG4.

 

[tsedge]

Same issues as Sara4711.
Also a MG4 Trophy LR, with heat pump.
Delivered in Feb 2023.
Have to set it to 27 in order to get any heating in the cabin.
So I definitely have the faulty temperature sensor.

But I also experienced twice that the heating isn’t working at all.
Both times it was solved by parking the car, exit and lock it.
Then when entering the car again, everything went back to normal.

This is not good at all.
During winter, I have a pretty iced car after 2 x 10 minutes preheating set on high.
On the same parkway we have our MG5 facelift LR that doesn’t have the heat pump. And that car is warm and have totally de-iced after 10 minutes of preheating!

So, as it doesn’t get particularly warm, sometimes fail to produce heat at all, and has to be set to +27 when it does work, and is extremely noisy when set to Auto, this car is not built for the climate we get during winter here in Scandinavia.

Apart from that, I love the MG4.

This sounds like a fault on your car. We leave our car set to 23C gives us around 20C and defrosts nicely in ten minutes. No heat pump on UK models.

I had heard that PTC heaters defrost more quickly than heat pumps, so perhaps that is part of it but if your heater isn't working, sounds like a dealer visit is needed.

 

[hubj540]

This sounds like a fault on your car. We leave our car set to 23C gives us around 20C and defrosts nicely in ten minutes. No heat pump on UK models.

I had heard that PTC heaters defrost more quickly than heat pumps, so perhaps that is part of it but if your heater isn't working, sounds like a dealer visit is needed.

Yes, having a heat pump should be a benefit, but as you confirm, the heating is more efficient on PTC heater. No doubt that it works much better on our MG5 without heat pump.

The tricky part is to get it fixed.
Because I do believe it to be a software issue rather than a hardware problem with the heat pump. That in combination with the sensor, probably.

And from what I can read here, there’s no software update available addressing the heating problems yet, or am I wrong?

 

[Eber]

And from what I can read here, there’s no software update available addressing the heating problems yet, or am I wrong?

No. I am bringing my car in again next week for the LKA update and the rear window heater has stopped working again. I asked about the heater issue(s), but my dealer said there is no solution yet. MG are aware, but that's basically it.

 

[ArTee]

No. I unlock and unplug the car and THEN the HAVC system does not start up.

That the car can't be preheated when plugged in is yet another issue.

When your car gets warm inside when set to 23°C then it obviously does not have the cabin sensor issue. Mine has. (See below ;-) ).

Just going through the forum now to see who else has my issues and it's pretty clear that I have the same. Pretty much no heating until 26-27C then it gets stupidly warm to the point that I have to lower it to 20C to get confortable. I do remember seeing some 80C+ in the app at least twice so I'd guess I have the same temperature sensor issue.

The question is - did you get it sorted and how? I only recently updated to R33 from R30 thinking it would do it but it didn't unfortunately...

 

[tsedge]

I don't have this and I am on R33. I would guess it is a car module rather than the infotainment that needs an update.

 

[Eber]

I don't have this and I am on R33. I would guess it is a car module rather than the infotainment that needs an update.

Yes. My dealer has applied update HE-32 which solves many heater issues for many customers - so he said ambiguously. Since ambient temperatures are above 10°C even at night now I can't really judge it properly.