VW Polo Aux Heater Repair Guide: Fix It Right

I had a similar issue with my 2003 VW Golf TDI. With some experience working on diesel engines, I can share my recent repair journey. The auxiliary heating system showed similar symptoms, no start condition and fault codes. After checking the blower motor and temperature sensor without finding issues, my trusted workshop diagnosed a defective glow plug in the heater core assembly. The repair involved: Complete diagnostic scan, Removal of auxiliary heater unit, Replacement of faulty glow plug, System reset and testing, Coolant leak check after reassembly Total cost came to 440€ including parts and labor. The heating system has worked flawlessly since the repair. To better assist with your specific case, could you provide: Current mileage, Any warning lights on dash, Whether you notice any coolant loss, If the regular cabin heating works normally, The exact fault code stored These details would help determine if your issue matches what I experienced or if it might be something different.

At 118149km, I faced this exact problem with my Polo. The diagnostic showed the heater core glow plug was faulty, along with a faulty temperature sensor. When removed, there was also a small coolant leak around the heater unit seals. The car service found two separate issues affecting the climate control system. First, the auxiliary heater component needed cleaning due to carbon buildup. Second, they discovered worn electrical connections to the control unit. Total repair cost was 580€, which included: New glow plug, Temperature sensor replacement, Heater unit seals, System cleaning, Coolant refill Regular cabin heating works perfectly now and no fault codes since the repair. The auxiliary heater starts reliably in all conditions.

Thanks for sharing those details about your Polo repair. Your experience matches what I encountered with my Golf TDI. The carbon buildup issue on the auxiliary heater is quite common on these VW diesels from that era. After my initial glow plug replacement, I also discovered similar electrical connection problems at the climate control unit. The temperature sensor readings were inconsistent due to corroded wiring, which explained some of the intermittent heating system behavior I noticed. I had the workshop do a thorough cleaning of the auxiliary heater unit while it was removed. The blower motor also benefited from this service, as it had collected quite a bit of debris over the years. Your repair cost of 580€ seems reasonable considering the full scope of work. Looking back, I should have requested the complete service you got, as it would have prevented my follow-up visits. The heating system maintenance really needs to be comprehensive to ensure reliable operation, especially with these age-related issues. Have you noticed improved fuel consumption since the repair? My auxiliary heater now cycles more efficiently during cold starts, which has helped reduce my winter fuel usage.

Thanks for confirming the diagnosis matches my Polo issues. The carbon buildup and electrical problems definitely explain the heating system failure symptoms I experienced. Since getting the auxiliary heater and climate control system properly repaired, I noticed much better cold weather performance. The blower motor runs quieter after the cleaning and the heater core warms up faster on cold starts. Fuel consumption has improved slightly this winter. The auxiliary heater cycles properly now instead of running constantly like it did before. No more coolant leaks or fault codes, which gives me confidence the repair addressed all the underlying problems. The 580€ repair cost was higher than expected but worth it for a complete fix rather than partial repairs that might have needed followup work. Having a properly functioning heating system is essential and the thorough service should prevent issues for years to come. Looking back, dealing with both the mechanical and electrical problems at once was the right approach. The comprehensive cleaning and new components have the whole system working like new again.