Is 250 Heating

[John Edgar]

I have owned my is 250 from new for 11 months - since Jan 07. At first I struggled a bit with the heating system but then it became warm and the issue went away. Now I find that once again I am unable simply to get the car at the right temperature. Either I am boiling hot at my feet and cold at the top or vice versa. It doesn't matter what I have the system set to, with or without the A/C on. Sometimes hot air comes out of the rear seat lower vents and at the same time cold air comes out of the front lower vents. Whether the eye level vents are on or off, either on the setting panel or directly turning them off, somehow we are still cold on top, especially at knee and lap level. Nothing we do seems to change this. Cold air always comes out of the top side vents (to the side windows) and these cannot be turned off. I have covered these over with insulating tape to try and improve matters and warm us up a bit, but still we get cold. Should I have to do this in a £30,000 car?

Does anybody know how to get this sytem working correctly? If you ask me it is too complicated for its own good. This is automation for its own sake and is completely unnecessary. I am thinking of asking the dealer to disconnect all of the automatic stuff so we can adjust it as we want it to be, and not as the car says it should be - wrongly.

Any help welcome with this.

John

[Rich_Bee]

Hi John,

The only fault could be a thermostat failure - this might be worth checking, or the electronic control function changing the heat exchanger/fan setting i suppose.

In your mail you don't mention just putting it on auto (don't have it on dual) and setting the temp to say 21. You'll need to leave it a few minutes to get settled but this should sort itself out. The only button to use then is the window one if you get steamed up/cold morning and then press this again to get back to normal. I only have trouble with mine when my wife puts the temp on her side to about 25 when we first get in because it's cold thinking this will warm it up quicker, when she only wants it on 21 in the first place

Rich.

[Kit77]

I only have trouble with mine when my wife puts the temp on her side to about 25 when we first get in because it's cold thinking this will warm it up quicker, when she only wants it on 21 in the first place

Rich.

Is this trait common to all wives/girlfriends/womankind? It sounds strangely familiar!

[Northern Boys Luv Gravy]

I've never had a problem with mine. I set it at 22 deg, on AUTO, when I got it and it has stayed that way ever since - I never touch it.

[Scarlet Pimpernell]

I only have trouble with mine when my wife puts the temp on her side to about 25 when we first get in because it's cold thinking this will warm it up quicker, when she only wants it on 21 in the first place

Rich.

Is this trait common to all wives/girlfriends/womankind? It sounds strangely familiar!

Very familiar. I think there should be a basic "Thermostatic Control Knob Course" offered free when you buy anything that has a thermostatic control...Our house heating goes up and down like a Yoyo, let alone the car...we must waste tonnes of Co2...all because someone in da house doesn't quite understand how Thermostat's work...

Anyway, I've found this issue of too hot too cold in cars too. Even my previous Audi did it...and an S class Merc (old shape) is the same too...

I think it's just not clever enough, as it has a limited number of sensors. I think you need 4 zone climatic control and double glazing to get it just right...

I find I set it to 21d, but withing 20 minutes of driving, I have to cool it down, then re-adjust to 21 and it's fine....strange...

[Infinity]

My only quibble with the heating is the interface lets you select a combination of one or two

vents to have the air come out.

Why isnt thier an ambient setting where air comes out from all the vents?

Rather than hot feet or dry eyes, why cant we be warm all over.

The easy cure in the winter is to set the heated seats to warn as the air won't

come on until the engine reaches tempreture to heat the coolant water.

And i'm at work by then

Infinity..

[Exiled]

Hi John,

The only fault could be a thermostat failure - this might be worth checking, or the electronic control function changing the heat exchanger/fan setting i suppose.

In your mail you don't mention just putting it on auto (don't have it on dual) and setting the temp to say 21. You'll need to leave it a few minutes to get settled but this should sort itself out. The only button to use then is the window one if you get steamed up/cold morning and then press this again to get back to normal. I only have trouble with mine when my wife puts the temp on her side to about 25 when we first get in because it's cold thinking this will warm it up quicker, when she only wants it on 21 in the first place

Rich.

We've all got wives like that, the solution to the problem is to get her really really hot before she gets in the car!

[Steve ( West Mids )]

We've all got wives like that, the solution to the problem is to get her really really hot before she gets in the car!

Fortunately the air conditioning is more contrallable ;)

[BlueyIS]

I only have trouble with mine when my wife puts the temp on her side to about 25 when we first get in because it's cold thinking this will warm it up quicker, when she only wants it on 21 in the first place

Rich.

Is this trait common to all wives/girlfriends/womankind? It sounds strangely familiar!

I agree

[Teeonethousand]

Like most others I pretty much did a 'set and forget' but I did accidentally hold the AUTO button a bit long and it went into a setting mode. A quick check in the book revealed that it was to do with the sensitivity between external air and recirculated switching.

It might be worth checking that yours is not out of whack - you never know maybe it could cause this?

[Colm]

If you don't like the auto settings, why not just turn the auto off, and control it manually using the mode switch?

I don't understand why you had to tape the side vents shut.....I'm sure mine has little roller switches to close them....in fact the roller switches even light up in the dark!

Colm

[John Edgar]

If you don't like the auto settings, why not just turn the auto off, and control it manually using the mode switch?

I don't understand why you had to tape the side vents shut.....I'm sure mine has little roller switches to close them....in fact the roller switches even light up in the dark!

Colm

I am talking about the window side vents which have no switches, unlike the face level side vents, which do. The window vents cannot therefore be switched off and after about 30 minutes driving will only deliver cold air. That is why I have taped them closed as I can fine no other way of stopping the flow of cold air.

John

[John Edgar]

Hi John,

The only fault could be a thermostat failure - this might be worth checking, or the electronic control function changing the heat exchanger/fan setting i suppose.

In your mail you don't mention just putting it on auto (don't have it on dual) and setting the temp to say 21. You'll need to leave it a few minutes to get settled but this should sort itself out. The only button to use then is the window one if you get steamed up/cold morning and then press this again to get back to normal. I only have trouble with mine when my wife puts the temp on her side to about 25 when we first get in because it's cold thinking this will warm it up quicker, when she only wants it on 21 in the first place

Rich.

I have tried every setting under the sun (and moon as well) with no effect. Yesterday we went out for a trip. We were warm for 1/2 hour and then cold air started issuing forth from the face level vents, even though the system was set for lower level only - no air to face level. That's with the little arrow pointing downwards - nothing else. So we turned up the lower heat only to get boiling hot feet and still cold air at the top. In fact the hotter you have it at the bottom - to get warm - the colder it gets at the top. It does this whether it is on auto or not. I just want to be warm all over! Anyway I have booked it into Lexus Brighton on Friday. I think I am going to get them to disconnect the top sensor so that we can just have 1 zone with the same temperature air being delivered all over.

I really do think the system, at least on my car, is too clever. As I said this is technology for the sake of it.

John

[Teeonethousand]

Hi John

I did a long journey over the last couple of days and, following this thread, I paid particular attention to the way the heating was working. Mine is the same as yours - after a while it puts out cooler air from the uper vents. This does not put me off too much but it did set me wondering if the logic of the software controlling the heating does this to 'freshen' the driver - particularly if the setting is quite warm.

When you are in the dealer perhaps you might ask if they have a logic diagram for the way the sensors/heating is designed to work ? I am with you generally on the technology being sometimes too clever - seems to do everything except what you want :=)

[Sliew]

I have owned my is 250 from new for 11 months - since Jan 07. At first I struggled a bit with the heating system but then it became warm and the issue went away. Now I find that once again I am unable simply to get the car at the right temperature. Either I am boiling hot at my feet and cold at the top or vice versa. It doesn't matter what I have the system set to, with or without the A/C on. Sometimes hot air comes out of the rear seat lower vents and at the same time cold air comes out of the front lower vents. Whether the eye level vents are on or off, either on the setting panel or directly turning them off, somehow we are still cold on top, especially at knee and lap level. Nothing we do seems to change this. Cold air always comes out of the top side vents (to the side windows) and these cannot be turned off. I have covered these over with insulating tape to try and improve matters and warm us up a bit, but still we get cold. Should I have to do this in a £30,000 car?

Does anybody know how to get this sytem working correctly? If you ask me it is too complicated for its own good. This is automation for its own sake and is completely unnecessary. I am thinking of asking the dealer to disconnect all of the automatic stuff so we can adjust it as we want it to be, and not as the car says it should be - wrongly.

Any help welcome with this.

John

Pls. try & check anything (eg. CD) missing in AC filter area to jam the interface of fresh door lip.

1. switch to recirculate mode

2. open the glove box and remove the shelf (up and then pull to side out)

3. Remove AC filter cover door which behind the glove box.

4. Now you can see the filter inside it and check anything missing in.

Sliew

[stevet]

Hi John

I had the same problem but it only occured after 12 months and 15k miles. So i presumed it must be something that i've changed. Anyway after going through all the menu's and changing one setting at a time i finally found one that worked and the car is now nice and warm all over.

I was simply to turn off the dual zone sensor (top right from the climate menu on MM). I now dont get cold air from the side vents.

Might be worth a try.