Audi TT Parking Heater Failure: Fix Tips & Costs

Had the same auxiliary heater problem on my 2014 Audi A5 2.0 TFSI. The climate control system showed similar symptoms, and the ventilation system was working normally except for the auxiliary heating function. The issue turned out to be more complex than just a temperature sensor. During diagnosis, the technician found that the auxiliary heater control module had failed, and there was a small coolant leak near the heating element. The coolant leak was causing the system to shut down as a safety measure. The repair involved replacing the control module and fixing the coolant leak. This was a serious issue that required specialized diagnostic equipment. The car heater problems should not be ignored as they can lead to more extensive damage if left unattended. If your auxiliary heater is not functioning, it would be wise to have it checked by an Audi specialist. The diagnostic process usually involves checking the entire heating circuit, including the control module, wiring, and heating element. These components are interconnected, and failure in one area can affect the entire system. Worth noting that a complete system scan is necessary as temperature sensor readings alone might not reveal the full extent of the problem.

Thanks for sharing your experience, really helps. My situation sounds quite similar with the symptoms you described, especially how the climate control and ventilation system work fine except for the auxiliary heater. I plan to take it to a specialist as you suggested. Just wondering, do you remember roughly how much you ended up paying for the full repair? Also, has everything been working properly since the fix, or have you noticed any other heating system issues popping up?

Just wanted to follow up, got the repairs done last week and it was exactly what my car heater needed. The mechanic found a defective glow plug in the auxiliary heater system, which was causing the complete shutdown of the heating function. Total cost came to 440 Euro for parts and labor, which seems reasonable for this type of specialized repair. The climate control system is now working flawlessly. The auxiliary heater kicks in properly during cold starts, and I have not experienced any error codes or malfunctions since the fix. When checking the system, they also did a full inspection of the coolant circuit and heat control components to ensure there were no other underlying issues. This repair completely resolved the problem, honestly wish I had done it sooner instead of waiting and wondering about the auxiliary heater malfunction. The car starts and warms up much better now, especially during colder mornings.

Thanks for the input. Finally got my car back from the mechanic yesterday after dealing with this heating system problem. My issue turned out to be pretty similar, a faulty auxiliary heater component plus some wiring issues in the control module. Total bill came to 520 Euro, bit more than expected but the car heater works perfectly now. They did a full check of the coolant system while they were at it and found everything else was fine. The climate control is responding much better, and the auxiliary heating kicks in exactly as it should. Really glad I went with a specialist shop instead of the general repair places I used before. They knew exactly what to look for and fixed it right the first time. Been running great for the past few days with no error codes or heating problems. Definitely worth getting it sorted properly rather than trying cheaper fixes that might not last.