S Klasse Hybrid reduced heating and water valve error

I had a similar issue with my S Klasse. Reduced car heating is a pain. The water valve, or heater control valve, regulates coolant flow. Check the wiring harness and connector first, a loose connection can trigger the error. A defective car valve can lead to engine overheating if it restricts coolant flow. Did you check for coolant leaks?

When you encountered this issue, did the diagnostic system indicate a specific fault code related to the valve, or was it a more generic error? I am trying to ascertain if a complete valve replacement is necessary, or if addressing the electrical connection will suffice.

My diagnostic system gave a specific fault code pointing directly to the heater control valve. While it could be the wiring, the fact that a code is present suggests the valve itself might be faulty. Given the symptoms and error code, I would advise a workshop visit for a proper diagnosis. If the valve is stuck closed, it could definitely cause engine overheating eventually.

I appreciate the clarification and advice. Based on your experience and the potential for engine overheating, I will schedule a workshop appointment for a thorough inspection and potential car valve replacement. Thank you for confirming the link between a defective valve and potential overheating issues.