I added the heated washer system "875 - Heated Washer System (SPC), $105" to my 2013 ML build, however the only reference that I can find is on the build sheet. I didn't find anything in the owners manual or even on a Google search...

Does anyone else have this option? Is it something that can be turned on/off, or is it permanently enabled? It seems that Mercedes run an extra line from the engine coolant system into the washer fluid reservoir, probably with a little radiator to get the washer fluid warm/hot.

I remember a rental Buick having this option, but it was electric, and was turned on manually by the driver. It was pretty neat to have steaming hot anti-freeze to clear a windscreen from ice buildup rather than having to scrape it by hand, though I see that GM had huge recall issues with their system and ended up disabling it on most cars due to risk of fire.

So I tried checking to see if the water was hot by sticking my fingers into the stream after a long trip (to make sure everything was warm like it was supposed to be), but all I got was a face full of methanol overspray heh... I read somewhere that Mercedes might regulate the temperature to around 120F, which might be why it didn't feel warm to the touch?

 

If it is linked to the engine like you said I would think its hot wen the engine is hot. And I would also think that it can't get too hot or it would crack a frozen windshield.

 

I have got winter package with my ML350 and it includes windscreen washer heating in addition to external engine heater and front seat heaters but I have not seen any instruction how it works anywhere. I am just curious if it works simultaneously with the external engine heater. But the problem is I am temporarily located in UAE and temperature never gets cold enough to be able to use the external heater I guess I need to wait until I ship my car back home

 

Official description from MB:
"The windscreen washer fluid reservoir and washer nozzles are heated, meaning they are better protected against icing up. This allows the windscreen to be cleaned more effectively at low temperatures.

The heated windscreen washer system comprises the following features:

■Heated windscreen washer nozzles
■Heated washer fluid reservoir
■Heated washer fluid hoses
■Heating circuit
■Auxiliary water pump
■Wiring"

 

I haven't looked in my rig but this is how it used to work. The fluid is heated by the radiant heat of the vehicles cooling system. Basically, two lines are run off the cars cooling system to a metal heating coil which sits inside the washer fluid reservoir. As the engine runs, hot coolant is circulated through the coil inside the reservoir. The radiant heat warms the washer fluid, making it easier for you to clean off your windows.

 

This will explain the problem and fix.

 

on a 2023/24 GLE does the washer fluid spray from the blade itself?