Mini Cooper Diesel Low Heating Output

Sounds familiar! I had a similar car heating issue with my old VW Golf. Turns out it was also a faulty automotive valve. Was your engine overheating at all?

Engine temperature remained normal. What type of valve was defective in your Golf? Was it related to the car heating system specifically?

Yes, in the Golf it was the valve that regulates coolant flow to the car heating core – basically a smaller radiator inside the dash that provides heat. I didn't notice engine overheating, but the car heating was barely working. Given your symptoms and the stored error, a valve blockage is definitely plausible. I'd suggest a workshop visit to confirm. It's usually a straightforward fix.

Identified defective water valve in my Mini Cooper Diesel. Cable/plug connection was the likely culprit. Replaced the valve; car heating now functional. Total cost 95€. Thanks for the input.