Heater core or not

Looking for direction on an issue i am having on my 14 passat tdi 70k miles. Last august vw replaced my heatercore due to it failed in the winter. Worked fine when i checked it and decided over the next several months to run the heat a littke just to circulate the fluid sitting in the heater core. Whent to check it and it blows cold air out of the passenger side hot on the drivers side and warm in the middle vents. Would this be a heater core issue or a blend door actuator motor.
Thanks for any input.
Mark Kraft

When we had the symptoms you describe on our '13 Passat (since turned in for buyback), it turned out to be the heater core, which was replaced under the extended warranty. The person on the passenger side of the car in a trip home from VA had to have a blanket over their legs to keep warm.

heater core for sure, passanger vents cold, center barly warm- drivers window hot-

My 2014 did the same thing in Jan 17 the dealer replaced the core and did the flush. it worked great for about 5 months and then back to the same thing, the car went back to the dealer and they did it again. It has been working fine since then, Both times it was done free of charge by the dealer since there is a TSB out on it. Also just fyi mileage or warranty has nothing to do with it, mine had over 100k miles on it when this whole thing happened. Good luck

The warranty extension for the heater core is 10 years/120,000 miles on '13 and '14s. Mine has been done twice at 41,000 miles in oct-nov '15 and 52,000 in oct '17 (car was parked for most of 18 months in between).