Mini Roadster Diesel Heating Issues

Hmm, that sounds similar to an issue I had with my Mini Countryman. Same symptoms, low car heating output. Did you check the coolant level? Also, the 'error memory' you mentioned - what specific code did it throw? Knowing the error code can really narrow down the possibilities. This automotive valve, the water valve you are mentioning, is responsible for regulating coolant flow to the heater core, so it makes sense that's the issue. It is part of the cooling system. Before you go replacing parts, I would also suggest checking the wiring and connections to the valve as you suggested. It could be a simple fix.

Coolant level is fine. I don't remember the exact error code, but the mechanic said it pointed to the water valve being faulty. Is it common for the cable or plug connection to be defective? Is there a way to test the valve?

Yeah, a faulty connection is definitely a possibility. I didn't try to test the valve myself, to be honest. I took mine straight to the workshop, and they confirmed it was the water valve. Saved me a lot of hassle. So yeah, going to the workshop would be the ideal solution.

Cheers for the insight! Just got it sorted at the workshop. Turns out it WAS the water valve – they quoted 95€, which seems about right. Car heating is back to normal. I appreciate your help!