Heating

[Dazza Tough]

The heating has stopped working correctly on my 2007 A6 TDI Quattro . On short journeys I have it on high but it blows only cold air , on longer journeys it would takes around 15 mins for the hot air to work but when I slow down in traffic it becomes cold air again . Any ideas what the issue is . TIA

[Steve Q]

The engine temp gauge read normal. As it could be the thermostat. 

In failing that you could do a diagnostic check to see if any fault codes flag up as there could be an issue with the heater module, control unit etc. 

[Dazza Tough]

Hi. I had a diagnostic test done for another issue, it did show climate control module 2 issues  ;1st  air quality sensor reads short to ground and 2nd coolant re circulation pump reads upper limited exceeded