Heaters

[Dec]

The car in the video was flooded because water drains at the bottom of the windscreen became blocked and water entered the cabin through the heater air vent located above the heater blower motor… seen in the video between 2:55 and 3:18.
The video states how to clear the blocked drains and not how to fix a flap that doesn’t close.
To find out how to check if this flap is not closeing properly you will need to follow what I say below.

You need to confirm if this flap is indeed not closing properly when the heater dial is set to 0.
To do that you need to remove the trim bits at the outside bottom of the windscreen so you can see the motor fan as seen in the video above between 2:55 and 3:18.

When you remove the windscreen trim and can see the motor fan, get someone to turn on the ignition and then the heater dial from 1 to 0 and back to 1, if the heater flap is working properly you will see it open and close as your assistant moves the dial between 0 and 1.

If the ignition is ON and the engine is not running, you can hear the heater flap open and close when you move the heating dial from 1 to 0, this however isn’t as good as seeing the flap open and close as described above.

Is the car heating and cooling working ok? Are you getting cold air if you turn the heater thumb wheels to Blue?

Dec

Your car was flooded in the same way, did you clear the blocked drains?

Dec

 

[MercMania]

I have unblocked the drains I just need to sort out y is there air coming through the vents with the heaters are off when I am driving when I am parked no air coming through

 

[MercMania]

When I start the car there's no air coming through the vents and when I start driving the air starts coming through the vents

 

[MercMania]

When am not even puting the heaters on

 

[Dec]

The link below is for a w210 and discusses this flap problem.
W210 recirculate + duovalve problems - Mercedes-Benz Forum

This link shows how the windscreen trim is removed so you can get sight of this flap from outside of the car, see… https://www.youtube.com/watch?v=7ca6h6HRskU

Dec

 

[MercMania]

Ok thank I need to have a proper look at it as when I started car today the heaters where on zero but the EC light came in after a bit and heaters kicked in my themselfs don't know whats going on with my car never had any issues before

 

[Dec]

You mean the aircon (EC) light came on without being pressed?

Dec

 

[MercMania]

I have that pressed all the time so I put heaters on I use EC that's what I was told if that light is on then its normal heaters if off its air con, so started my car the EC light came on after a while so the the heaters without me putting heaters on the control was on zero

 

[MercMania]

Last few days the heating controls where on off but heat was coming through vents

 

[MercMania]

Today heat coming through vents with the EC light on and heater control on zero

 

[Dec]

Edit; EC button is for turning air con OFF or ON it doesn’t make any difference to the air being hot or cold, that's the job of the Red/Blue thumb wheels.

EC button Red light ON means air con is OFF.
EC button Red light OFF means air con is ON

Thumb wheel turned to Red means Hot air through air vents.
Thumb wheel turned to Blue means cold air through air vents
Heater dial set to 0 means flap closed so no air should comes into cabin from outside.

You should have the air con ON (EC button Red light OFF) all year round, summer and winter.
You can have the air con on with the thumb wheel turned to Red (hot) or Blue (cold)

Is the Red light in the REST switch ON or OFF?… it should usually be OFF.
REST switch is the switch below the EC switch.

Study the User Manual, Here … http://www.mbusa.com/vcm/MB/DigitalAssets/pdfmb/ownersmanual/2000_cclass.pdf

Dec

 

[MercMania]

I normaly use the EC light on don't matter if am using hot or cold air that's always selected so when I turn heaters up that light comes on then when on zero it goes off but today it was just on all the time even with heaters on zero and the rest light always off

 

[MercMania]

EC button Red light ON means air con is OFF.
You should have the air con ON (EC button Red light OFF) all year round, summer and winter.

U just sent me that which had confussed me abit is that same think but different answers

 

[MercMania]

Ok if I keep EC on all year the gas on air con will finish and take more fuel is that correct

 

[Dec]

My understanding is that it’s good for the air con system to have the air con ON all the time, I think Mercedes recommend that you keep it on, that’s why there is the Red light that comes On when the air con is OFF… to warn you that the air con is OFF.

I don’t think it makes a significant difference to fuel consumption, you will use more fuel alright with it ON but not that much more, I don’t think, I have no idea what the figures are for having it on or OFF.

I think you lose about 10% of your gas every year anyway, that’s normal, I have no idea if turning it OFF will reduce this loss of gas, you are suppose to top up the gas every year to compensate for the loss.

Dec

 

[MercMania]

Ok than well first I need to find out why I was having air come through vents when the heater was on zero and the other one why was the heaters working today with the controller was on zero

 

[Dec]

If the EC light is coming ON automatically, then the air con is turned itself OFF because it need a service.

Dec

 

[MercMania]

But the heaters are kicking in aswell on zero, and last time it needed service didnt have this issue got it serviced about a year ago but not used aircon

 

[Dec]

If the heater air intake flap is stuck open then that will explain everything.

If your air con is in good working order then you should turn it on to test it, you should be getting very cold air at the vents if all is well with the air conditioning system.

Dec

 

[MercMania]

Ok I try that so I need to take everything apart again