VW Bora Parking Heater Failure, DIY Help Needed

Having experienced a similar auxiliary heater failure on my VW Golf 2000 1.8T, I can relate to this issue. The symptoms match what I encountered, a functioning blower but complete auxiliary heater failure with error messages. The main cause was a faulty heater control module combined with a coolant leak in the heater core system. The ventilation system worked normally, but the auxiliary heater remained unresponsive regardless of settings. In my case, it required: Complete diagnostic scan, Replacement of auxiliary heater control unit, Repair of coolant system leaks, System reset and recalibration This was indeed a serious repair requiring specialized knowledge of VW heating systems. The heat control components in these models are known to develop issues around this mileage range. The repair took several days due to the complexity of accessing the heater core and auxiliary heating components. Based on the symptoms described, it sounds very similar to what I experienced. Would strongly recommend having it checked by a VW specialist who can properly diagnose the auxiliary heater system.

Thanks for sharing your experience with the heater core repair. I also faced issues with my Bora about 6 months ago, car would blow cold air even with the heat control set to maximum. After diagnosis, they found a clogged heater core and some electrical issues with the auxiliary heating system. Did the repairs fully solve the problem for you? Wondering what the total cost was and if any other heating system issues came up since then. My repair bill ended up being quite hefty but at least the ventilation system has worked flawlessly since.

Thanks for asking about the follow-up results. After taking it to a certified VW specialist, the auxiliary heater problem was completely resolved. The main issue turned out to be a defective glow plug, which caused the error messages and prevented the heater from starting. The temperature sensor readings are now accurate and the heat control system works perfectly. Total repair cost came to 440€ including parts and labor. Compared to your heater core replacement, this was relatively straightforward since no major components needed removal. The auxiliary heater now starts reliably every time and maintains consistent heat output. No additional heating system problems have occurred in the past months. The coolant levels have remained stable with no signs of leaks. For anyone facing similar issues, having a proper diagnostic scan is crucial since auxiliary heater problems can stem from various components in these VW models. Getting it fixed by a qualified technician ultimately saved time and prevented potential damage to other heating system parts.

Thanks everyone for the helpful replies. After dealing with this issue, I finally got my Bora fixed last week. Took it to an authorized VW service center where they ran a full diagnostic scan. The ventilation system was actually fine, but they found the auxiliary heater had a burnt-out glow plug and a failing temperature sensor. The repair took about 4 hours and cost 380€ total. They replaced both parts and recalibrated the heating system. The blower motor is now working perfectly with the auxiliary heat, and no more error messages appear on the dash. Much better experience than my previous mechanic who wanted to replace the entire heater core without proper diagnosis. Always worth finding a specialist who really knows these systems. The car starts and heats up quickly now, even in cold weather. Definitely recommend getting a proper diagnostic scan first rather than guessing at the problem.