I have a 2.5 v6 tdi without air con and has manual controls and the heater is fantastic on and gives out really hot air . I also have a 1.9 tdi with air con and the electronic control , the heater is pathetic , I have flushed through the heater matrix and it flows freely , I have bled the system and when the engine is running the heater hoses get hot , but I still only get warm air through the heater , any suggestions , winters coming !!!!!!!