My autistic son threw crumbs down all the vents. I tried to vacuum them up, but the vacuum wasn't working. Then I forgot about the crumbs. =(Now my cooling/heat system is broken. It was an OLD system, and had been giving me problems since the beginning. I think it was on the verge of collapse a looooong time ago.Could the crumbs in the vents have caused the whole system to break down? It doesn't seem likely to me.
no but it may have helped if the system is that old and was never cleaned
The unit should have blown the crumbs out into the room if it was the hot air vent. Crumbs in a cold air return would be caught in the filter.
The only way crumbs in the vents would cause a fire is if they ended up all the way back at the unit and sat on the heat exchanger (even then very unlikely) or if it is electric heat and the crumbs gathered on the heating elements (still pretty unlikely). It is most likely the unit had internal issues that caused the fire.
its unlikely that is the cause you will have to get a professional to evaluate.
