2005 Volkswagen Golf Q&A

2005 Volkswagen Golf Question: My heaters blow cold on driver side hit on passenger side, passenger floor wet

I have replaced heater matrix but there is trapped air coming back up into my water tank it bubbles and overflows if i take the cap off after driver. Been told its the head but no creamy stuff on oil cap or dipstick and no white smoke. Also the air blocks from pipes have been cleared..any suggestions please? Its a peugeot 307cc -
Answer 1
possible heater issue. -