We have a forced hot air system that is about 12 years old. Occasionaly when the blower starts up I hear a rattling noise that gets increasing louder and then fades away. ANy suggestions on what might be causing this? something loose? what usually wears out to cause this and where/how should I diagnose. Thanks
Could be a bearing rubbing, but then this would be just guessing. Have a professional check it out, since it could be cheaper now than a repair later.
imho,
tom @
I haven't heard your noise but it could be the blower fan blade, either the collar loose on the shaft or the blade (maybe a squirrel cage) loose on the collar.
For some strange reaso;n I couldn't get my motor out the first try, and since I had to go on a business trip in a couple days, I called a repair company. The joker changed the motor and reused the blade. When I told him that it was just as noisy as it had been, he denied it, but he was wrong. And stupid or lying.
He took the motor away, but I called the office 20 minutes later when I realized this, and I got the motor back. I complained to them but got nowhere. Years later the head of the company said I should have complained to him directly, and although I don't know if it would have helped or not, I should have, if only so I could write a better story here.
Anyhow, since I now knew it was only the blade loose on the collar, I wasn't worried about a fire starting while I was out of town for almost a week. Got back around early January, and a couple weeks later the noise stopped. It was quiet and ok for a couple years, and then it got much worse and I had to buy a new blade. I still have the motor. Maybe I'll use it for a bench tool, or in case the new motor fails.
I had the same problem with the furnace here.
The rattling comes very *likely* from worn out bearings of the blower-motor, and/or the squirrel-cage blower might be out of balance. There might also be the option that only a screw is loose.
In my case there was significant play, try carefully to slide the shaft/motor w/ the squirrel cage left and right if there is any play. Here it was so bad that the blower actually touched the side of the housing..therefore creating the rattling noise.
I'd defintly let an HSV guy let that check out. Other option would be DiY which would mean getting the whole housing w/ the cage out, checking the motor, screws, bearings...even cleaning the cage with a hose or replacing the blower, maybe even the whole motor.
Greetings
That was probably what my guy thought, and though I believe you that the odds were with that reason, in my case, he probably didn't even listen to the sound, or he would have known it wasn't bearings. I think I knew it wasn't bearings, but I was young and trusting, and figured I didn't have to question him before he started replacing things.
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