Heater blower and temp problem

[Kerabo]

2006 220cdi
Can anyone point me in the right direction to solve this problem please.

i was thinking my climate control was not very sensitive so I was blowing the dust from my heater sensors where the mini fan is in the roof and at the bottom where the controls are. I also done a flap reset.
Now if set it on auto as soon as the engine is up to running temp my heater runs full speed at all switch positions and apart from the very first cold setting every position gives max hot. The fist position gives very cold air.

I thought I must have damaged a sensor with the air gun but after buying a replacement heater control and looking inside there is nothing fragile That I could hurt. I thought I may have blocked the small fan with dust but it is spinning, at least at the bottom. The roof one I am not sure about.
So it is able to supply both hot and cold air But only at full speed and no in between settings.
The heater fan will run slow and as it should until the engine is running temp But then goes full speed.
With manual controls I do have a speed control of the fan but not the temp, it’s full hot only or very cold on the first setting.

Any idea what may have happened? Apart from the flap reset and blowing cobwebs out I touched nothing.
Thanks

 

[Automac29]

2006 220cdi
Can anyone point me in the right direction to solve this problem please.

i was thinking my climate control was not very sensitive so I was blowing the dust from my heater sensors where the mini fan is in the roof and at the bottom where the controls are. I also done a flap reset.
Now if set it on auto as soon as the engine is up to running temp my heater runs full speed at all switch positions and apart from the very first cold setting every position gives max hot. The fist position gives very cold air.

I thought I must have damaged a sensor with the air gun but after buying a replacement heater control and looking inside there is nothing fragile That I could hurt. I thought I may have blocked the small fan with dust but it is spinning, at least at the bottom. The roof one I am not sure about.
So it is able to supply both hot and cold air But only at full speed and no in between settings.
The heater fan will run slow and as it should until the engine is running temp But then goes full speed.
With manual controls I do have a speed control of the fan but not the temp, it’s full hot only or very cold on the first setting.

Any idea what may have happened? Apart from the flap reset and blowing cobwebs out I touched nothing.
Thanks

Hi Kerabo - did you manage to fix this problem? I have an identical one after a screen change!!

 

[Kerabo]

Hi Kerabo - did you manage to fix this problem? I have an identical one after a screen change!!

Hello
sorry for the delay.
I managed to get a replacement top unit with the same number but it made no difference.
When I can remember where I put it for safe keeping I have the bottom climate control to change to see if it helps.
This seems to have started when after seeing on You tube how to do a flap reset And a gentle blow out of the vents on the control.,

this one has climate control.

I assume on these the hot cold is by a flap and not water control?

ken

 

[wrdcc01]

To start with I have no idea about the C220 heat and ventilation but how about this. In "auto" the system will control the fan and as soon as the engine coolant gets warmer than the temperature you've set the system will try to achieve this as soon as possible by driving the fan at high speed. When in manual you get control of the fan and get to chose how quickly the selected temperature is reached. You say that in manual it is either full hot or full cold which means there is no temperature control beyond this. This sounds like a water valve being on or off. Same when in auto. My thought is that you have damaged the temperature sensors so only allowing extremes. Thoughts based on W124 so there's a 2 in it!

 

[Kerabo]

Thanks for your detailed reply.
On the stop for cold gives ice cold but one click above that is full hot and full fan speed all the way round the control.

I did get the water valve working on an E Class for someone but assumed my C Class was all controlled inside the heater with flaps.
I dont know so would be pleased to hear.

Thanks Ken

 

[wrdcc01]

Ken, it does have a hot water shut off valve on the bulkhead part number A0002036264. Which I guess is working as you're getting hot or cold (you are correct in that the heat is directed and adjusted by the blend doors) so check the temp' sensors if you can. No doubt Star could show if there is any output from them in live data. Maybe try and vacuum where you used the air line, some of the crap may have blown onto them.
Dean

 

[Kerabo]

Ken, it does have a hot water shut off valve on the bulkhead part number A0002036264. Which I guess is working as you're getting hot or cold (you are correct in that the heat is directed and adjusted by the blend doors) so check the temp' sensors if you can. No doubt Star could show if there is any output from them in live data. Maybe try and vacuum where you used the air line, some of the crap may have blown onto them.
Dean

Thank you Dean
I will have a search for that valve.
I still feel when I done a flap reset something happened. As you say if it blows hot and cold so whatever controls the temp is working. It just has no inbetween temp, just full hot or full cold.
Thanks
Ken