Heating Problem

[robin61]

Hi all, Thought I would join this group to see if anyone can help. I have a 21 plate Corolla Hybrid and whenever the weather is damp outside I always have to have the A/C on. If not then the windows mist up very quickly.

Have never had this with any other brand of car i have owned. The car is obviously drawing in moisture from somewhere. All carpets are dry and no leaks etc. from anywhere.

Has anyone else had the same problem and if so did you ever get it resolved. Its been into my local dealer and they say they can't find anything wrong. Very frustrating as to have to have the a/c on all the time if I want this to stop.

Comments would be welcome

 

Thanks All...........

[FROSTYBALLS]

Do you use the air con in conjunction with the heater?

Have a look at the first post of:

Also using dehumidifier bags, and closing the air vents when parking may help absorb some moisture.

[TonyHSD]

Hi and welcome. 
The Toyota Corolla hybrid has very advanced heating and cooling system. 
It is highly recommended to use the system in auto mode with ac always ON. 
Eco/fast function off. Recirculating off. 

Set temperature at 22C° and auto mode ON plus AC ON. 
This is all you need to do once and that’s all.  
If you ever feel too hot or too cold you can readjust temperature settings by 1 or 2 degrees up or down and that’s all. Set and forget is all you need. 
For the moisture in the car you need to cheek boot and spare wheel well. The usual water ingress in any Toyota happens through rear lights clusters. 
Check also carpets on rear foot wells. 
Clean windscreen from inside with clean microfibre cloth and pure water. Clean few times until streak free. 
That’s all. 
 

[taxidriver50005]

I second cheak spare wheel well... Water can pool in there... 

[Dylanfan]

A lot of this may be that it’s a hybrid. The engine is not running all the time and as Tony says, the system is very advanced so ac on all the time helps to eliminate moisture in the air.

[Cyker]

Get a good glass cleaner spray and microfibre cloth and clean the inside of your windows to an inch of their transparent lives, even if they look clean!

I'm not sure why but newer cars seem to be much more prone to the buildup of off-gassing from the plastics on the inside of the windows, and for some reason it encourages misting to form on them.

My Mk4 was a death-trap this time of year when I first bought it because it would mist up something chronic and it was only by chance when I was driving home in low sun I could see a rainbow-refraction of whatever-it-is on the windows.

Once I had cleaned it all off (And it took a surprisingly amount of cleaning!) the car was far less prone to misting up. I had to give it a good clean regularly until the 'new car smell' faded away and it's been much better since, although I still need to clean it if e.g. I've transported something oily like fish and chips in the car.

I only cleaned my side of the windscreen in summer and I can already see the passenger side is misting up much more readily than my side!

[robin61]

1 hour ago, TonyHSD said:

Hi and welcome. 
The Toyota Corolla hybrid has very advanced heating and cooling system. 
It is highly recommended to use the system in auto mode with ac always ON. 
Eco/fast function off. Recirculating off. 

Set temperature at 22C° and auto mode ON plus AC ON. 
This is all you need to do once and that’s all.  
If you ever feel too hot or too cold you can readjust temperature settings by 1 or 2 degrees up or down and that’s all. Set and forget is all you need. 
For the moisture in the car you need to cheek boot and spare wheel well. The usual water ingress in any Toyota happens through rear lights clusters. 
Check also carpets on rear foot wells. 
Clean windscreen from inside with clean microfibre cloth and pure water. Clean few times until streak free. 
That’s all. 
 

Thanks. Just after I bought the car April last year there was a water leak and they finally found there was a crack in one of the seals on the hatch so replace the whole of the hatch door. Water was pooling up under the boot mat and since replaced not one drop of water is coming in. My wife’s Ford I can drive all day long with a/c off and no misting whatsoever but I’m my Toyota I could never do that

[TonyHSD]

15 minutes ago, robin61 said:

Thanks. Just after I bought the car April last year there was a water leak and they finally found there was a crack in one of the seals on the hatch so replace the whole of the hatch door. Water was pooling up under the boot mat and since replaced not one drop of water is coming in. My wife’s Ford I can drive all day long with a/c off and no misting whatsoever but I’m my Toyota I could never do that

You can but you need make sure you have correct settings on hvac control and if you don’t want ac on that’s fine just double check your settings are as follow: 

Cabin temperature - 22C°

Air intake from outside 

Air flow feet and windscreen 

Fan speed 2 

Recirculating mode off

A C off

Eco/Fast off

Just leave it like that and you will not have any problems. 
It will take a little bit longer for the windscreen to clear off as the only dry air will be supplied by the engine heat. 
Hybrids does indeed run colder than any other petrol or diesel cars but when you have cabin temperature set at 20-22C° the engine will run as necessary to provide warm air. 

[Chuffmonkey]

I agree with Tony above, My car is left in Auto AC all year around, I vary the temperatures from anything from 18, 20, 22 and the last few days 24 degrees, its been cold but I do only drive in a t-shirt or shirt and put my coat on at destination arrival  😂.

I have had no problems with that setting. Thinking about my previous cars, I have never turned AC off. 

[fred88]

People tend to think that AC is only for use in summer when in fact it is very useful in winter too. It acts like a dehumidifier, dries the air and clears the windscreen far more quickly when it's on.

[ThomasL]

All my Toyota's have been misty (petrol diesel and hybrid). Maybe it's manufacturer-specific.

I use rain-x anti fog, it works but make sure to put the tiniest amount on or it's worse!

[Stopeter44]

23 hours ago, robin61 said:

and whenever the weather is damp outside I always have to have the A/C on. If not then the windows mist up very quickly.

99+% of the time, since 2016 +/-, I run AC whether heating or cooling the car. As @TonyHSD has said, set it and forget it.