Audi Q7 Parking Heater Failure: Cost & Fix Guide

Had similar issues with my 2009 Audi A6 3.0 TDI. The auxiliary heater stopped working completely during cold weather. Initially thought it was the blower motor, but diagnostic revealed a defective glow plug in the auxiliary heater unit. The repair required removing several components to access the auxiliary heater assembly. The main symptoms matched yours, heater would not activate and threw error codes. The climate control system worked normally, but the parking heater function was completely dead. This turned out to be a serious issue requiring specialized knowledge. Beyond the glow plug replacement, technicians found a small coolant leak in the auxiliary heater unit. The temperature sensor also needed replacement as it was providing incorrect readings to the control unit. The repair took two full days at the shop. Without proper fixing, this issue can potentially damage other heating system components. Would strongly suggest having it checked by an Audi specialist who understands these auxiliary heater systems, as DIY attempts often lead to more complications. Most common causes in order of likelihood: Defective glow plug, Failed temperature sensor, Coolant leak in heater unit, Control module issues

Thanks for sharing your experience. I just had the exact same issue with my Q7 last winter. After reading this, I am pretty sure it was also the glow plug causing trouble since the symptoms match perfectly. My parking heater also refused to activate and kept showing errors. The problem actually got worse over time and started affecting the ventilation system completely. Did your heater core or any other components need replacement in the months after the initial repair? My mechanic mentioned possible follow-up issues but I would like to know what to expect. Also curious about the total repair cost for your case since I am still dealing with warranty claims for mine. Were you able to get any coverage from Audi?

After having the auxiliary heater fixed at the dealership, no additional problems emerged with the ventilation system or heater core. The repair completely resolved the issue, and everything has worked flawlessly for over a year now. The total repair cost came to 440 Euro for replacing the defective glow plug. This included labor costs for accessing and dismantling the auxiliary heater unit. Unfortunately, due to the age of the vehicle, Audi would not cover any portion under warranty. The coolant leak I initially mentioned was minor and got fixed during the same service. The technicians pressure tested the entire heating system afterward to ensure there were no remaining issues. Looking back, getting it fixed promptly prevented any cascade of problems with other components. The car heater now works perfectly in all weather conditions, and the parking heater activates reliably every time. Based on my experience, once the glow plug is replaced properly, you should not expect any follow-up issues with the ventilation system or other heating components. If your mechanic is suggesting potential future problems, it might be worth getting a second opinion from an Audi specialist who regularly works with these auxiliary heater systems.

Thanks for the input. I finally took my Q7 to a specialist after putting it off for too long. The heat control unit was completely dead, and just like others mentioned, it was mainly due to a faulty glow plug. Getting to the auxiliary heater was quite a job. The mechanic had to remove multiple parts just to access it. While they were in there, they found a small coolant leak, similar to what others experienced. The entire heating system needed a thorough check. Total bill came to 520 Euro including parts and labor. No luck with warranty coverage due to the age of the car. But honestly, the peace of mind was worth it. The parking heater now works perfectly, and the ventilation system is back to normal. For anyone facing similar issues, dont wait like I did. Getting it fixed early definitely prevents bigger problems down the line. The whole repair took about 2.5 days, but at least now I can rely on my car heater working properly during cold weather.