Audi Q3 Cold Start Issues: PTC Heater Troubleshooting

I had a very similar issue with my 2020 Audi Q5 last winter. As someone with some DIY maintenance experience, I initially tried basic troubleshooting but quickly realized the heating system needed professional attention. The symptoms matched yours exactly, rough cold starts, increased fuel consumption, and sluggish temperature control. The HVAC system was clearly struggling to maintain proper heat. After taking it to a certified workshop, they diagnosed a faulty electric auxiliary heater. The electrical fault was causing the PTC heating element to malfunction, which explained the extended warm-up times and engine performance issues. The complete repair cost me 350 Euro, including parts and labor. Since the fix, the heating system works perfectly again, cold starts are smooth, and fuel consumption returned to normal. Before suggesting specific solutions, could you share: Current mileage on your Q3, When did the symptoms first appear, Any recent maintenance history, Which specific fault codes were shown, Are you noticing any unusual sounds from the heater This information would help determine if your issue is identical to what I experienced with my Q5 and whether the same repair approach would be suitable.

Current mileage is 127655 KM, with the last service completed at an authorized workshop just before these issues started. They found codes P0530 and P0531 during scanning. The cold air problems began about 2 weeks ago. When starting in cold weather, there is a distinct clicking sound from the front of the vehicle, followed by complete loss of heat from the HVAC system. The temperature control seems erratic, sometimes blowing cold air even when set to maximum heat. The PTC heater symptoms match exactly what you described. Fuel consumption has increased by about 15% since these issues started. Did your repair also include checking the temperature sensors, or was it just the heating element replacement?

Thanks for those details. Based on the error codes and symptoms you described, your Q3 is showing the exact same behavior my Q5 had. The clicking sound from the front is particularly telling, I had that same issue before the repair. In my case, the workshop did a complete diagnostic of the HVAC system. They found that while the PTC heater was the main problem, two temperature sensors also needed calibration. The blower motor was functioning correctly, but the faulty heater element was causing the temperature control system to misread cabin temperatures. The total scope of my repair included: PTC heater element replacement, Temperature sensor calibration, Full system diagnostic, Heater control module reset After the fix, the clicking noise disappeared completely and the heating system regained proper temperature control. The fuel consumption dropped back to normal within about 2 tank fills. Given your similar symptoms and identical error codes, I would recommend having the complete heating system checked, not just the PTC element. In my experience, the extra diagnostic time was worth it to prevent any recurring issues.

Thank you for sharing your repair experience. Your detailed explanation about the temperature sensors really helps clarify what I should expect. The clicking noise has actually gotten worse this week, making the cold air problems more noticeable each morning. I will schedule a complete HVAC system diagnostic to address both the PTC heater and sensor calibration issues. The 15% fuel consumption increase is concerning enough to justify the full repair cost, especially since the blower motor still works but fails to deliver proper heat. One last question regarding your repair, did the workshop mention anything about the life expectancy of the new heating element? I want to ensure any replacement parts will last longer than the original ones that failed. Also planning to note down those error codes P0530 and P0531 to discuss with the technicians. I appreciate you confirming that the clicking sound and temperature control issues were resolved after your repair. This gives me confidence that addressing the complete heating system rather than just the heater element is the right approach.