W203 Heater problem

[ricko61]

I've got a C270 CDI, with an annoying heater problem. The air con system works fine and the heater is fine when the engine's warm. The problem is that when the engine is cold, even with the temperature control wound right up to max, it still blows freezing cold air at you. With the winter coming up, this is going to cause me earache every time my other half drives it. I've tried the soft reset using info found on another thread.
Any other ideas please?

 

[Robbo]

I'm not sure whether the the C270 was fitted with an auxiliary heater. If it wasn't, then there is nothing you can do as car heaters works by using heat from the engine to warm the cabin air. If the engine is cold, then there is no heat! Diesels take quite a long time to heat up too.

Maybe a c270 owner will be able to say if an auxiliary heater was fitted as standard. if there is an auxiliary heater fitted, then there sounds like there may be a problem with it.

 

[whitenemesis]

Do you have it set on "Auto"?

It certainly shouldn't blow anything until its warmed up enough. Mine does nothing until the engine has warmed up, usually 5min even on the coldest mornings.

 

[whitenemesis]

Check you have the auxillary heater option set in the cluster. IRC all CDIs have this option. Its a small electric heater that boosts the coolant temp if the outside air is <7degC, helps cabin air temp as well as engine warm-up.

 

[Rory]

I'm not sure if they do have an electric aux heater? IIRC the Aux heater in the convenience menu causes the a/c compressor to act in 'reverse' and assist the cabin warm up - you can turn it off by pressing the a/c button.

One thing that occurs to me, is are you pressing the front screen demist button? This will cause max fan speed and max airflow to the screen.

Mine is the same as whitenemesis's car - in auto operation, the airflow gradually increases as the engine warms up.

 

[lexuscol]

I have a C220 which has the aux heater but you have to enable it in the systems.

 

[fredfloggle]

I thought the block heater was diesel powered? I can't see any electrical heater having enough umph to warm up the block without flattening the battery.
As mentioned it does have to be enabled , and you do need to run the system in auto.

 

[Rory]

The diesel block heaters are generally only fitted in very cold climates.

Some Ford's have an electric heater (powered by the car, once running) to assist warm up - I've seen comments where they fail, and the cars just won't warm up in winter.

Honda use the heat-pump effect of the reverse a/c on their diesels.

 

[fredfloggle]

I'm pretty sure that the block heater fitted to merc diesels is standard equipment - you just need to enable it through the dash menu .

 

[television]

Aux heaters are the webasto type under the offside front wing when fitted and are diesel. Sweden uses 230volt block heaters.

If the air distribution on the 203 is out of sinc,re set it

203

To reset heater flaps and actuators

Switch on ignition.

Press recirculated air and defrost buttons on control panel together for longer than 5 seconds.

The LED's in the defrost and recirculated air buttons flash alternately.

Wait until the LED's stop flashing (approx 30 sec) system set to defrost LED on.

Switch off ignition.

After 40 sec re start engine.

 

[Dunhamkid]

Mine is definitely electrically powered and is activated by a switch adjacent to the ashtray

 

[1998K]

as far as I've seen on the instruction manual (please note my Country), don't confuse between the auxilliary heater (that normally is an option) and the "supplementary" heater. I'm not sure if the wording "supplementary" is correct but it's a Mercedes standard device (may be only in diesel engine) to speed up the cabin temperature.

As said already it's possible to switch between different operation: always ON, always OFF, ON with auto but in any case it is operated with temperature below 7 deg

 

[ricko61]

Thanks for the responses guys. I'll check out this aux heater thing tomorrow.

 

[Diesel Benz]

At least my car is using the notation "Auxiliary heater" for the diesel powered heater while the electric heater would be called "Heater booster".

I believe all CDIs should have one or the other, or both (both would be the case of the aux heater installed as an option). Early W210 CDIs had the aux heater without a heater booster. Later the aux heater was replaced by the heater booster but the aux heater is still an option.

The electric heater booster is not heating the coolant (directly at least) but is an element at the AC heat exchanger and directly heats the air. I would not call it "small", on a W211 it can have 1700 or 1800 W power, just about as much as the alternator can produce. Of course it also helps the engine heat up because engine coolant heat is used less, and also the engine produces more heat because of the high alternator load.

The AC switch can be programmed differently, either the heater booster is always on or is switched off in eco mode. Older cars have the switch off control active.

The external 230V electricity based block heater is a completely different feature. It never has been an option from MB factory (to my knowledge).

 

[television]

The external 230V electricity based block heater is a completely different feature. It never has been an option from MB factory (to my knowledge).

I had the 230volt mains block heater on my 123 and 124 when living in Sweden, the socket on the 123 was in the bumper, and lead on the 124

 

[television]

Look at the ML here, it has one, some cars on Benzworld have them

http://www.buysell.com/root/detail/...9901/2006_SUBARU_B9_TRIBECA_50000kms_5dr.aspx

 

[Diesel Benz]

I had the 230volt mains block heater on my 123 and 124 when living in Sweden, the socket on the 123 was in the bumper, and lead on the 124

I've had this socket and heater on several of my cars (not on either one currently though), I'm not claiming it would not exist.

But it never came from the factory, I've never seen it on the German price list which usually indicates if an accessory is available from the factory.

 

[television]

I've had this socket and heater on several of my cars (not on either one currently though), I'm not claiming it would not exist.

But it never came from the factory, I've never seen it on the German price list which usually indicates if an accessory is available from the factory.

Fine, that could be correct, the main Mercedes dealer fitted the one in the 124 for me. I agree that no mention of these things is in any MB service data

 

[Rory]

At least my car is using the notation "Auxiliary heater" for the diesel powered heater while the electric heater would be called "Heater booster".

I believe all CDIs should have one or the other, or both (both would be the case of the aux heater installed as an option). Early W210 CDIs had the aux heater without a heater booster. Later the aux heater was replaced by the heater booster but the aux heater is still an option.

The electric heater booster is not heating the coolant (directly at least) but is an element at the AC heat exchanger and directly heats the air. I would not call it "small", on a W211 it can have 1700 or 1800 W power, just about as much as the alternator can produce. Of course it also helps the engine heat up because engine coolant heat is used less, and also the engine produces more heat because of the high alternator load.

The AC switch can be programmed differently, either the heater booster is always on or is switched off in eco mode. Older cars have the switch off control active.

Thanks for that - mine (late 2004 W203 C270CDi) has the Heater Boost function, but I didn't realise it was an electic element. As the setting are, Auto, Off, Off with A/C Off, I assumed it was tied in to the a/c compressor (like the Honda system, where it works as a heat pump). The Off with A/C Off seems a little odd, as with the a/c on then the electric boost heater and the cooling effect of the a/c would be working against each other.

There's certainly no Aux diesel heater option listed in the brochure for my car.

I really don't use mine much for short journeys anyway, but I really try to avoid them in winter as it seems to take about an absolute age to warm up thoroughly.

 

[Diesel Benz]

Thanks for that - mine (late 2004 W203 C270CDi) has the Heater Boost function, but I didn't realise it was an electic element. As the setting are, Auto, Off, Off with A/C Off, I assumed it was tied in to the a/c compressor (like the Honda system, where it works as a heat pump). The Off with A/C Off seems a little odd, as with the a/c on then the electric boost heater and the cooling effect of the a/c would be working against each other.

There's certainly no Aux diesel heater option listed in the brochure for my car.

I really don't use mine much for short journeys anyway, but I really try to avoid them in winter as it seems to take about an absolute age to warm up thoroughly.

Your brochure may not have the aux heater, I guess it would be rare for the UK market anyway. But it comes with option code 228 and definitely is available for a W211 (I assume also fro RHD cars).

Yes it looks odd that the heater booster is controlled with the AC button and both are on or off at the same time. I did not check the exact figures but it is likely that the AC anyway would not kick in at temperatures where the heater booster does. The aux heater on-temperature can be adjusted (it can be set to come on automatically or only manually, at least on a W221), not sure if DAS would allow that for the heater booster.