GjBW203

My w203 2003 C220 has AC off option on the control panel, i have noticed some other older or newer w203 has EC Rest or EC instead of AC off!

Does this mean that my vehicle has no residual heating option when the engine is off?

Also how long does it take for your vehicle to reach over 80 degree engine heat on a 17-20degree weather?

I think mine either has a thermostat problem or something else is wrong coz it takes some driving to reach around 75degree.


Many thanks

Plutoe

First, the EC button is not a residual heat button----if the EC button lamp is lite it, means that your compressor is off---there is a separate button for the residual heat option plus you must have a functioning coolant circulation pump.

Regarding your coolant temp question----you have an issue,replace the thermostat!!

somedude

Yes, some models have the EC/Rest button.

When the engine is running, pushing EC/Rest turns off the AC compressor, EConomy mode is on and the top LED turns on.
When the engine is turned off, pushing the same EC/Rest button turns on residual heating and the bottom LED lights up.

My W203 heats up in minutes in winter time, so if yours takes a long time (please define "long") then you may have a thermostat leak or failure.

GjBW203

Plutoe, i know that EC is not resdiual heat but its in the same button.
I didnt know that it requires an additional pump for the "Rest" but now i know mine does not have it.

Thanks man

GjBW203

Somedude, yesterday i drove it for like 20min urban driving and some 6km highway and bearly reached 70 i guess it thermostat also. Is there any other way i can test it apart fron blocking the radiator?

Thanks

somedude

Well you could feel (carefully so that you don't get burned) the hoses or measure their temperatures. If the hoses (and rad for that matter) get warm shortly after the engine has been turned on, then the thermostat might be open.

Mine went to 180F in just 5 minutes of driving this morning (mid 60's outside temp), so you may very well have a thermostat that is stuck open.

In regards to the Rest function, that doesn't use a circulation pump, it just takes advantage of the fact that the coolant in the system is hot and it will turn on the heater fan at low speed to transfer some of that heat into the car. As coolant cools off during this process it will circulate within the system due to convection.

lflex617

I had to replace my heater control I went to a junk yard for a replacement. I brought it back and noticed the AC buttons are labeled differently my old one says ac off and the new ones says esc will these affect how I use the AC?

BF_JC230

Yes.
HVAC CONTROL is built date dependent. It may work, and you just relearn how to use A/C. And it may not work. Ensure you normalize the flaps holding front defrost and recirculate.
STF. Especially for those of use that did the digital swap.