Why does our vacuum smell HORRIBLY whenever we vacuum?

My husband SWEARS that he replaced the belt in our vacuum the correct way, but since he replaced it, every time we vacuum, the entire house smells like burnt rubber... it's AWFUL! At this point, I'd rather have dirty carpets than have that smell!

Is there a chance that the belt is not right somehow?

The vacuum is a bagless Eureka Altima.

Thank you!
Sara

just take out the belt and put in again maybe your husband don't put it right or the belt move when your husband close the vaccum .

Did he remove the old one?