Were working, flipped the switch one day, weird noise and bam. Blows ice cold but not out of my vents. if you switch to heat it blows from floor i believe but will have to double check. any ideas? Searched but didn't really know what to search for so I came up empty!

 

wildvents. sorta sounds like them but then again its sounds like a blendor or something else
im sure there will be someone chiming in shortly, seems like a common problem

 

looks like you gotts vac.leak just checkall your vac. lines i just replaced some of mine and it went back to normal after that and mite be plenum or what he said

 

I'll check my vac lines in the morning!