What are some of the vw passat tdi heater problems?

If the heater on the VW Passat tdi is having issues then there are some common reasons. If the heater core has been clogged, with dust or debris, then it will not function at full power. This could mean cooler air or a less powerful air stream from the vent. Cleaning it will fix this issue. If the heater won't work at all then the control motor may not be getting power. This could be a broken motor or bad wire but is more likely a burnt-out fuse. To get to the fuse box look to the left of the steering wheel look for a small seam or crack along the dash. Using a screwdriver or prybar You will want to pop this open. On the inside, You will find a bunch of fuses. On the back of the panel that You pulled open, You will see a diagram that will show You what each of the fuses is for. If this is not on the back of the panel then You can also find it in the owner's annual for the vehicle. Once You have figured out which fuse You need simply pull it out. The two sections that stick up should be connected by a thin strip of metal. If this has been broken then the fuse is no good and will need to be replaced. If this strip is there then the fuse is fine and can be popped back in. New fuses will cost You about 10 dollars, so they are pretty cheap.