VW Golf Heating Failure Despite Service Visit

Had this exact issue with a 2011 VW Passat TDI. The symptoms match what happens when the air distribution flap actuator fails inside the dashboard panel. The climate control system has multiple flaps controlling where air flows, and when one actuator fails, it creates uneven heating and persistent fogging. In my case, the mechanic found both a disconnected plug and a worn actuator mechanism behind the climate control unit. This required partial dashboard removal to access the HVAC unit components. The repair involved replacing the actuator assembly and checking all related connections. While not a severe mechanical issue, it requires specific diagnostic equipment to properly test the electronic signals to the flap motors. The heater core itself was fine, the problem was purely in the air distribution system. If left unfixed, it can lead to complete failure of the defrost function. Worth getting a second opinion from a shop with VW-specific diagnostic tools, as generic scanners might not show the detailed HVAC codes needed for proper diagnosis.

Thanks for that detailed explanation. I had a similar situation with my Golf last winter. The blower motor was working but the air distribution was completely messed up, warm air only came through unusual vents and the windshield kept fogging up badly. Would love to know what the final repair cost was in your case. My fix ended up involving the entire climate control unit replacement plus labor, and I want to compare prices. Also, has everything stayed working properly since the repair? No new HVAC issues popping up?

After getting the faulty defrost air distribution flap fixed last month, the ventilation system has been working perfectly. The repair was straightforward, turned out to be just a loose cable connection to the flap actuator, which the mechanic sorted for 95€. Much simpler than expected, no need for a complete climate control unit replacement. The temperature regulation is now spot-on, with proper air circulation to all vents. More importantly, the windshield fogging issues have completely disappeared. The Passat maintains clear visibility even during cold morning starts, which was my main concern. The early diagnosis saved me from more extensive repairs. If your Golf is showing similar symptoms, definitely get it checked before winter sets in. The cost difference between fixing a cable versus replacing the entire unit makes it worth investigating the simpler solutions first.

Thanks for the advice. Just got back from the new mechanic and wanted to share my experience. The ventilation system issue was indeed similar, they found a damaged actuator in the dashboard panel causing the temperature regulation problems. Total repair came to 280€ including parts and labor. While not cheap, its way less than the 650€ quote I got for a complete climate control unit replacement at the first shop. The mechanic showed me the old actuator which was completely stuck. The HVAC unit now works perfectly, warm air flows correctly through all vents and the windshield stays clear. Definitely worth getting that second opinion. The whole repair took about 3 hours and they even did a full system check to make sure there were no other potential issues. Just wanted to close this thread and thank everyone who helped diagnose the problem. Really saved me from an unnecessary expensive repair.