Noisy Exhaust Blower - QF Santa Fe

[biglar]

I got the roaring sound cleared up in my stove the other day - mostly due to plugged firepot holes - and now it's started making a "whining" sound when the exhaust blower comes on. It's been almost silent up till now. Sounds almost like a piece of string or straw or something is caught on the impeller. Concerned that it may be bearings, tho' I did oil the bearings last spring, I pulled that motor right out of there yesterday for a full inspection.

There was a little brownish crud on the impeller and a little in the passages, but nothing that I'd feel concerned about. I looked up in there as much as I could with a mechanic's mirror and flashlight and see no obstructions of any kind. Nothing sticking out, nothing.

When slowing down it makes almost a growling sound, for all the world like using a clothes pin to hold a piece of cardboard in a bicycle's spokes, but, as I say, there's nothing in there. Bearings are like new - shaft spins freely and silently and there is no play in the bearings.

Yah, it just now started up as I'm typing this and as it spooled up it kind of went "oooooorrrrrrrrrooowwwwww" as it gained speed. (how do you like my interpretation ?? Now it's at speed and giving a steady rrrrrrrrrrrr sound. Don't like this much, but again, don't see anything wrong.

Anybody out there seen anything like this ??

Thanks

Lar.

 

[SmokeyTheBear]

If the motor has oil ports they are likely supposed to be periodically oiled. What does the motor plate or your manual have to say about oiling frequency.

If there is any buildup on the fan blades or between the impeller and mounting plate it may be slightly out of balance.

 

[biglar]

If the motor has oil ports they are likely supposed to be periodically oiled. What does the motor plate or your manual have to say about oiling frequency.

If there is any buildup on the fan blades or between the impeller and mounting plate it may be slightly out of balance.

I oiled it last spring and yesterday I oiled it again while I had it out. I used a light non-detergent turbine oil and let it soak down into the batting around each bearing. Fan blades are brownish and the coating wipes off with a fingertip. No chunks that I could see, nothing in the passages.........nothing.

Spun the motor by hand while I had it out and it spins smoothly and silently. I've done a tremendous amount of this kind of work in my career and this one has me baffled.

Thanks for the reply.

Lar.

 

[SmokeyTheBear]

Any chance of the unit when mounted being out of alignment (unequal tightening of the nuts holding the assembly to the cavity)?

Noises inside an echo chamber aren't the easiest things to track down.