Rough-Running Nivus: PTC Heater Causing Cold Start Issues

Had similar symptoms with a 2017 VW T-Roc 1.5 TSI. The heating system showed identical error codes, and the temperature control was not working properly during cold starts. The blower motor was running, but no warm air was coming through the vents. The PTC (Positive Temperature Coefficient) heater was indeed the culprit. These auxiliary electric heaters support the main heating system, especially during cold starts when the engine hasnt reached operating temperature. The repair involved replacing the complete PTC heater unit. This was a serious job requiring partial dismantling of the dashboard to access the heating system components. The cold air issue was immediately resolved after replacement, and fuel consumption returned to normal levels. The symptoms you describe, rough cold starts and increased fuel consumption, match exactly what happens when the PTC heater fails. The engine compensates for the failed electric auxiliary heater by running richer mixture during warm-up, leading to higher fuel consumption. Would recommend getting this checked quickly, as continuing to run with a faulty heating element can lead to increased strain on other HVAC components.

Thanks for sharing your experience. The symptoms match exactly what I am experiencing with my Nivus. Really helpful to know about the dashboard dismantling part, will help me plan ahead for the repair time. Can you recall approximately how much the complete PTC heater repair cost? Also, curious if you had any other heating or cold start issues since the replacement was done? It makes sense that my high fuel consumption is linked to the heater not working properly. Going to get this fixed before winter hits full force and cold air becomes a bigger problem.

After getting the PTC heater fixed at the shop, my heating system works perfectly. The repair cost came to 350€ for replacing the defective electric auxiliary heater. Since the repair, cold starts are smooth and my fuel consumption returned to normal levels. The HVAC system now delivers proper warm air even during initial startup, and I have not experienced any heating issues in the past months. The blower motor delivers consistent airflow and the heat works exactly as intended. The investment was worth it, as the car no longer needs to compensate with extra fuel during cold starts. Plus, having reliable heat during winter drives makes a huge difference in comfort. The dashboard reassembly was done properly and everything works as it should. This is a common issue with these models, so getting it fixed by someone familiar with the heating system components is important. The improvement in performance and fuel efficiency was noticeable immediately after the repair.

Thanks for the feedback. Finally went to get this fixed last week and wanted to share my experience. The mechanic confirmed the faulty PTC heater diagnosis and found the heating element was completely dead. Total repair cost ended up at 420€ including labor. The job took about 4 hours since they had to remove parts of the dashboard to access the heating system. Worth noting that prices might vary depending on your location and shop. The difference is remarkable. Cold starts are now smooth, the cold air issue is completely gone, and the heat works perfectly. Most importantly, my fuel consumption has dropped back to normal levels. The mechanic mentioned they see this issue fairly regularly with similar models. One tip, make sure to book ahead since the dashboard disassembly means the car needs to be in the shop for most of the day. Really glad I got this sorted before the temperature drops further.