Mercedes C Klasse Hybrid Heating Issue

I have a C Klasse, though I can't recall the year exactly, and your problem sounds very similar to what I went through last winter Reduced heating, error codes... Does your engine temp seem normal Any weird smells It could be the valve, sure, but have you checked the coolant level A coolant leak could definitely explain the lack of heat Are you sure it's the valve itself and not just a bad connection Those plugs can get corroded sometimes

The engine temperature appears normal, and I haven't detected any unusual odors I haven't personally inspected the coolant level, but the diagnostic report didn't indicate any abnormalities Is there a straightforward method to assess the connections without specialized equipment

Well, without proper tools, checking those connections is tricky You could visually inspect them for obvious corrosion or damage, but beyond that, it's tough to say definitively If the diagnostic pointed to the valve itself, and you aren't seeing obvious coolant leaks, it still seems likely that the valve is defective Honestly, for 95€, it might be worth just having a workshop take a look They can pressure test the system and properly diagnose the valve and connections

Given the uncertainties, I scheduled an appointment with a certified Mercedes-Benz workshop Upon inspection, they confirmed that the water valve was indeed defective due to an internal fault, and they proceeded with the replacement as initially estimated Thanks again for your time and assistance