Heaters not working

[len_merclover]

I have no heat coming from my blowers!!! Any ideas....?

 

[jberks]

sorry - no - mine did it for a few days a couple of months ago but just settled down again and has been fine since. The dealer couldn't find anything. I don't think it's the duovalve as it was both sides - maybe a computer glitch.

 

[len_merclover]

well its been going on for sometime now no heat at all.... when u say computer glitch what is the best way to sort this?

 

[jberks]

I wondered whether it was a glitch in the controller - maybe reset by disconnecting the battery for a while. Guessing really though. It does sound like something they can reset though, as it's too new to be suffering from mechanical causes yet.

 

[jmack01]

Same problem

I have just discovered the same problem with my 2003 E240. Heater fan blowing fine but only cold air on both sides irrespective of the heater dial settings. My wife says this problem occurred for a short period last year but sorted itself out so she didn't mention it!

About six months ago I was getting a "switch off consumers" warning and asked MB to check it out. They changed the consumers battery (which lives under the bonnet tucked under the air con unit -and which I was unaware existed). This seemed to cure the alarm message problem. Apparently the same message flashed again recently at startup and since then the heater has not worked.

The car has not been driven much recently and I wonder if this has caused the batteries to partially discharge. Could this give rise to possible control system glitches? The car starts fine and it doesn't give the usual signs of a "flat battery".

I am tempted to try the "disconnect the battery suggestion" and hope that things reset - it works with my computer so why not the car!
If I do this though will I have to reset anything manually and any guidance on this would be appreciated.

regards,
James

 

[len_merclover]

Yes ....... I will try d/c the battery..... is there anything I need to do before and after? or is it simply a case of d/c and then r/c. . . .

 

[Ellsy Tanners]

Your heater shut off valve isnt working, a common problem, its located under the brake fluid resoivior.
Quite hard to change if you have'nt done one before. There's not alot of room down there!!

 

[jberks]

ah ok - I guess it sticks then, as faults seem to be intermittent.

 

[bigasotonuk]

I accept that the duo valve can stick, but it still equally could be the heater control panel as this feeds the duo valve and controls its opening and shutting, I checked this on my AMG by electrically disconnecting the duo valve as it will automatically default to max heater temp.

 

[Ellsy Tanners]

This is such a common fault that 999 times out of 1000 when a 211 has no heat its the shut off valve.

 

[jmack01]

I seem to have resolved the issue with my W211 heater problem (at least for the moment). The cure? I ran the engine up to temperature, turned the heater controls so that heat was being demanded. I then took a small hammer and a length of 3/4 inch softwood dowelling and placing dowelling against the offending valve, gave it a few (gentle) taps. As Ellsy says the valve is very hard to get at on the W211. The result of the above was instant heat which seems to have been regulating fine all day.

I'm hoping that the valve was just a bit stuck after a summer not being used.

Thank you all for your help, without which I would not have known what to hit!

Len - you might want to try the same ploy, it costs nothing and if you are careful does no harm.

James

 

[jmack01]

I seem to have resolved the issue with my W211 heater problem (at least for the moment). The cure? I ran the engine up to temperature, turned the heater controls so that heat was being demanded. I then took a small hammer and a length of 3/4 inch softwood dowelling and placing dowelling against the offending valve, gave it a few (gentle) taps. As Ellsy says the valve is very hard to get at on the W211. The result of the above was instant heat which seems to have been regulating fine all day.

I'm hoping that the valve was just a bit stuck after a summer not being used.

Thank you all for your help, without which I would not have known what to hit!

Len - you might want to try the same ploy, it costs nothing and if you are careful does no harm.

James