W221 cold in the rear only?

[DSK]

The mrs says it’s quite cold in the back of the w221 350 bluetec, mainly she says her back is cold and it seems to be blowing cold from the footwell, Despite me shutting the vents to off in the rear.

The car gets up to temperature really quick for a diesel and also I notice no issues with the heating and a/c controls upfront so no idea what she’s complaining about from where I’m sat.

Is there a setting one needs to use to ensure the rear of the car gets the same temperature as front?


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[bembo449]

Have you set heating to full / fan and made sure its on floor vents only ?

 

[DSK]

Ah no.

I just tend to have blow mode set to floor, body screen, set to 21C. It’s how it was when I bought it and not had any need to touch it.

I also switched the a/c off but that made no difference.


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[bembo449]

No harm in experimenting pal , my bmw had a cold setting on the central level i didn't know about , made the cabin cold as , turned it to hot , jobs a good un

 

[Blobcat]

Is she sitting on the same side as you, or is she on the pax side and the temp is set lower on that side?

Leave the AC on and set everything to auto with a 22-24’ temp on her side

 

[DSK]

Is she sitting on the same side as you, or is she on the pax side and the temp is set lower on that side?

Leave the AC on and set everything to auto with a 22-24’ temp on her side

Yes sits behind me.

Nothing is set to auto at the moment.

Temperatures for both sides are equal.

Thanks blobcat will be able to do that easily on the return journey from Oxford so I’ll report back once home.


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[Botus]

my fathers car doesn't heat the back unless the front is set to auto.... it must be a fault but that fix works (but its a w211 not a 221)

the other issue 221's can have rear AC or not, if you get a display in the back you get individual real AC controls and these have a valve block under the front wing behind the drivers wheel - 400 quid and they go wrong - but normally with uncontrollable too much heat in the back.

All models get a nasty 50 quid plastic valve by the wipers that goes wrong and all heating goes away.... part 170

FG 221.026 - HOT WATER LINES > Mercedes EPC Online > nemigaparts.com

Parts catalogs. Spare parts catalog Mercedes EPC Online. Mercedes. Car. HOT WATER LINES.

nemigaparts.com

 

[mioba]

..... so no idea what she’s complaining about from where I’m sat.
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Thats blokes. for you

 

[DSK]

Thanks for that. Not overly fancy heating controls in the back of mine other than on/off sliders.

I’ll try auto with ac as soon as we set off, as suggested. This will probably explain why she whinged in the cls also.


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[DSK]

Thanks to all for the advice and comments. I had a pleasant drive back as the Mrs fell asleep after telling me the back of the cabin is all good.

So auto switches on, ac on and this seemed to solve it straight away.

I also found something by accident under the ac menu in that stupid console thing, foot-well temperature! (It was set to the coldest setting). Why on earth would you want the footwell to be a different temperature to the cabin, then why not have a simple same button dial for it.


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[Botus]

ah - just read your post correctly - yes - if you go to the bottom middle "AC" menu choice on the comand screen and press the comand knob down you get a load more choices, one is footwell temp offset +- 2 either side on std
another is diffuse / focus / something else, its sort of vague and tends to increase air flow to hand vents on focused... diffuse is quieter and less obvious

I never use Auto, but in last 3 years my heat is dwindling and another forum member is having the same issue. I need a setpoint of 25C to get he heat of 21C in winter now, same with submariner1. Then on USA forum they all report this is the usual behaviour and its normal that valve needs to be swapped out. At 52US$ is not going to be high quality is it?

I suspect that valve is wrong on mine - we covered the other day - if u have a std screen then the plastic scuttle trim by the wipers can be taken off and its an easy job - if its aftermarket rubbish, the plastic trim can never go back right, as it clips on to stick on rubbish, rather than bonded metal on the lower edge of the screen, and on fake screens it just tears off

 

[DSK]

ah - just read your post correctly - yes - if you go to the bottom middle "AC" menu choice on the comand screen and press the comand knob down you get a load more choices, one is footwell temp offset +- 2 either side on std
another is diffuse / focus / something else, its sort of vague and tends to increase air flow to hand vents on focused... diffuse is quieter and less obvious

I never use Auto, but in last 3 years my heat is dwindling and another forum member is having the same issue. I need a setpoint of 25C to get he heat of 21C in winter now, same with submariner1. Then on USA forum they all report this is the usual behaviour and its normal that valve needs to be swapped out. At 52US$ is not going to be high quality is it?

I suspect that valve is wrong on mine - we covered the other day - if u have a std screen then the plastic scuttle trim by the wipers can be taken off and its an easy job - if its aftermarket rubbish, the plastic trim can never go back right, as it clips on to stick on rubbish, rather than bonded metal on the lower edge of the screen, and on fake screens it just tears off

Thanks for explaining the focused and diffused functionality!! I like quiet so I will change mine to diffuse!

Who knows what that’s supposed to mean otherwise. With the stupid console gadgetry the reprobates could easily put a little description next to the choices explaining what they do, it’s not like there’s no space or implantation issues with that, typical modern half arsed crap.

I’m glad the taxi spec satisfied me enough to not have to go to plan B which was S600/65 options!


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[Botus]

Thanks for explaining the focused and diffused functionality!! I like quiet so I will change mine to diffuse!

its why I never use auto on any car.... when the HVAC is right the 9 temp sensors that manage the 221 interior temp control based on your "thermostat set point" works perfectly on

fan 3 both sides
all vents fully open
all air flow on big arrows to all three locations (both sides)
footwell +1
diffused air flow distribution
21C in summer
22 C winter

aside for that temp tweak by 1 degree summer to winter - never ever touch them again for the cars entire lifetime - no crazy noises, no fiddling,