DIYbanter - View Single Post - Gas heater makes high-pitched whining noise but it's NOT the blower???

writes:
Thanks for all the advice. I found what I think is the inducer fan
after opening up my Carrier WeatherMaker 8000 (about 4 years old) and
oiled it with wd40 where I could reach, but it still makes the noise.
Perhaps it is the bad bearings Jonathan Kamens mentions.

Several comments:

1) I believe that the lubricated parts (if any) of most fans for this
type of application are sealed such that lubricating the unsealed
portion won't help.

2) If, indeed, the unsealed portion of the fan was previously oiled or
greased, then the WD40 you added will probably break down that
oil/grease, thus making the problem worse.

3) WD40 is flammable.

4) I believe that the air which passes through this fan is rather hot.

BTW, I called Carrier and there is absolutely no technical help of any
kind offered. I can understand that with something so potentially
dangerous they don't dare give out advice to consumers,

Yes, indeed. Your attempt to fix the problem yourself may have made
it worse and/or caused a dangerous situation. I suggest you pay a
professional for a service call.