where are the bleed valves?

hi i am new here and was wondering if someone can help me i have just changed the thermostst on a peugeot expert 1.9td 2000 as had no heating through heaters now i have but water is coming back up through the expantion tank cap i have replaced the cap and can only find the air release valve on the rad top right was wondering where the others are if any please help if can dean