C2 Heating Issue

I had similar grief with my C2's heater. First, check the coolant level; even a small leak can cause poor heating. Is the engine reaching normal operating temperature? A bad thermostat could also affect the heater core. Is the valve blocked?

Coolant is fine, and the engine heats up normally. The error code points to the water valve circuit. What did you find with your C2?

The water valve was the problem in my case. It's fairly common. I'd suggest a workshop for diagnosis and repair. I strongly suspect the valve needs replacing, but it should be checked thoroughly.

Thanks for the insight. The workshop confirmed the water valve was defective. The repair was 95€. Replacing it fixed the heating and cleared the error code.