When the furnace was first installed it was fine and now a few days later it makes a banging/clunking noise when it turns on and shuts off. Is this a serious problem that we should be concerned about? I have tried talking to the installer and don't seem to be getting anywhere. Can anyone give us a clue as to where to look in the basement to see if there is a problem? Thanks

If it's a new install, don`t just talk get the installer back out there to find the problem,, might not be much of a problem but it is something you shouldn`t have to live with. Its his job to take care of it,, just make sure it is coming from the furnace and not something else in your basement

Sounds like a blower wheel or hub problem. This maybe from a loose hub or as simple as something like paper or plastic inside the wheel (blower). Get it done fast, I waited too long. Tom