Another !@#$ Warranty issue!

Well, I got my new Keystone Premier Bullet 19' in January. Living in New York I brought it home & parked it. I did try out the heater, worked fine. As you may know, early last week we had a cold front move in & while camping we needed the heat on in the morning. It came on but so did the AC Fan. Fan only. So it was like they were fighting each other. Having some other warranty work done I added this. Well they told me at Camping World of Kingston that the reason is because the vent was dirty. This is my 5th camper and I have never experienced this one before. I asked them if they cleaned it out. They said only if I pay! Okay. Why? Because it's customer maintenance and I didn't bring it in within a month of purchase. I don't even know what vent we are talking about (on the phone). They say the one from the outside in. Then I was told a tech used an air hose and blew it out and the issue is fixed.

Huh? What just happened here. I will follow up when I pick it up!