Why is Model Y useless at demisting windscreen?

[Sixer]

I have had a couple of Teslas now and my Model Y is the worst without exception in clearing the windscreen of condensation. Even if I let the car sit for an hour on an evening, I have to go through the full rigmarole of demisting and waiting for the condensation to disappear before I pop to the corner shop. Nothing is held in the car that’s damp or wet and I have no leaks of water. Max demist setting takes at least 8/9 mins having timed it. Is this common on this model?

 

[Andywil]

I have had a couple of Teslas now and my Model Y is the worst without exception in clearing the windscreen of condensation. Even if I let the car sit for an hour on an evening, I have to go through the full rigmarole of demisting and waiting for the condensation to disappear before I pop to the corner shop. Nothing is held in the car that’s damp or wet and I have no leaks of water. Max demist setting takes at least 8/9 mins having timed it. Is this common on this model?

Do you have air conditioning on as this would help.

 

[Sixer]

If it’s user error please correct me. I just use auto all of the time when I drive. When I get in the car and it’s misted up I press the front windscreen icon twice to get it to show max.

 

[BissetY]

Can’t say I have noticed this on my Model Y. I also can’t make it to my local shop (less than 2 minutes away) without the cabin being at a comfortable temperature.

Sounds like somehow there is excess moisture in the car.

 

[Morpheus84]

If it’s user error please correct me. I just use auto all of the time when I drive. When I get in the car and it’s misted up I press the front windscreen icon twice to get it to show max.

This is something wrong with either the HVAC in the car or excess moisture. Do you vape in the car? Have you cleaned the inside of the windscreen properly?

I’ve had my MY over a year and the windscreen always clears quickly.

A few MY have had issues with water ingress pooling in rear passenger footwells. These car have also reported bad condensation issues.

 

[Bikeman]

It does not take much humidity to fog a windshield. One thing that helps before a car get into winter service is to start with absolutely clean glass. I suffered with the problem with mine all last winter and with other cars. I finally began watching YouTube videos on how to super-clean interior auto glass. What a difference. This needs to be done a few times during the winter season to be effective. It won't eliminate the fogging or freezing, but it sure helps. Floor mats should be free of accumulating water and snow otherwise the humidity keeps building up inside.

And the A/C ON is another helper to de-humidify the area as well.

 

[Buzzliteyear]

Have you replaced the cabin air filters?
it could be as simple as that. Do you have recirculation on?

 

[Jason71]

I notice this last night for the first time left somewhere at 10 PM. It was 3 degrees so the AC probably not effective. On the way out earlier a car drove though a deep puddle on the other side of the road an absubtely drenched the car. I wondered if some moisture for into the ventilation air intake?
Never had an issue before.

 

[Big Earl]

My dad is having problems with windshield fogging in his 2023 Model Y. He had been running the system in manual mode but says the problem persists in automatic mode. I’m going to take a look at it tomorrow. No such issues in our 3s or X.

 

[AndrewGR]

Certainly takes longer in my heat pump Y than it did in the pre heat pump 3. However pressing the windscreen heat button twice to show Max will generally clear the screen in a couple of minutes. I keep a microfibre cloth to hand to clear the worst of any moisture if necessary. AC needs to be on and not in recirc mode to enable effective dehumidification.

 

[Sixer]

Car is less than 6 months old no smoking or vaping. Never use recirculation. No damp or wet areas. I am going to check under the panels under the bonnet for leaves later this morning. Good point about cleaning the windscreen. I did that a few months ago and I know that can help. In other cars I’ve simply put on the blowers and watched the condensation creep back. I. On the MY I put on the blowers on max on the windscreen and watch people outside the car comment on how loud that electric car is as the heat pump gets excited

 

[AndyWarrington]

Car is less than 6 months old no smoking or vaping. Never use recirculation. No damp or wet areas. I am going to check under the panels under the bonnet for leaves later this morning. Good point about cleaning the windscreen. I did that a few months ago and I know that can help. In other cars I’ve simply put on the blowers and watched the condensation creep back. I. On the MY I put on the blowers on max on the windscreen and watch people outside the car comment on how loud that electric car is as the heat pump gets excited

I don't see AC on listed here, AC really helps demisting quickly (AC is for hot & cold applications - not just cooling; a common misconception)

A side observation: I'm always amazed when I see cars on the roads, motorways more worryingly @ 70+mph and I can't see the driver due to misting on all the windows! How do some folks survive

 

[GeorgeSymonds]

I had the issue yesterday for the first time in our MY. It seemed to mist up quickly having stopped for only an hour. i leave it all on Auto like every other car I've owned and just hit the front demist twice qucikly (to get MAX) when I have the problem.

Turning the cabin heaters on remotely a few minutes before you go out will aleviate the problem but something seems to have changed, Might just be good old software and Tesla have opted for a different use of the heatpump when driving for efficiency (which is great) at the expense of this type of unintended consequence. #speculation.

 

[Jason71]

Everyone is (rightly) saying to use AC but in cold weather car AC can ice up so typically it has temperature and or icing sensors and shuts down in these conditions. As such, sometimes when it would be beneficial for demisting it may not actually be running even if you have it turned on.
I have no idea what the operating conditions are for the AC portion of the Tesla HVAC system but when demisting in cold weather this could be a factor.

if mine persists, as an experiment, I am going to take my dehumidifier stick it in the car for an hour with the air circulating and see how much moisture it pulls from the system and whether that has any benefits beyond the very next drive.

 

[Pink Duck]

I’ve found that on particularly humid mornings/evenings that I can’t just demist the front windscreen then a short while into drive enable HEPA/BWDM. There’s usually a second go at needing to demist after the additional humidity from main filter and cabin air filters are blown forcibly through while achieving positive cabin pressure.

There was certainly a lot of persistent overnight rainfall in the East.

 

[CDB_]

Watched a few videos where YouTubers highlighted a possible cause being the air intake on the HVAC being close to the drainage channels for the windscreen. This could be the source of the moisture and would explain why it takes so long to clear

 

[M1tch]

I use these in all my cars. Really good and the cars never mist up

https://amzn.eu/d/bJXaR9a

 

[Jason71]

Watched a few videos where YouTubers highlighted a possible cause being the air intake on the HVAC being close to the drainage channels for the windscreen. This could be the source of the moisture and would explain why it takes so long to clear

this is basically what I was wondering when I posted earlier. All was fine then I was deluged by a car that drove fast through a massive puddle on the other side of the road yesterday. I stopped soon after and when I got back in the screen was steamed up like I have never seen before.

 

[Sixer]

Update - I’ve spent the last week driving around solely using AC and not with Auto enabled. No issues whatsoever so I am putting it down to that.

 

[Foxsbiscuits]

Update - I’ve spent the last week driving around solely using AC and not with Auto enabled. No issues whatsoever so I am putting it down to that.

Hmm. Why not use auto and AC? That's what I do and my windscreen clears in seconds from a cold start.