NEED HELP ASAP - problem with forced air furnace blowers

[CowboyAndy]

Hey all, I have a problem with my newly installed Newmac cl86 wood/oil furnace. I am desperate for help right now, I hope this is something that is easily fixed...

Right after we installed it, we had a problem where the blowers sounded like they had marbles in it, turned out it was slightly off kilter, but now is dead on balls level.

Last night (this morning, actually) out of nowhere, it started making this "grinding gears" sound. The blowers would come on and sound normally, then the "marbles" sound would start building up gradually and after a few seconds sounds like grinding gears and would start the sequence of sounds over until they shut off. I went down to investigate, but being half asleep and not knowing much about hvac anyways, the only thing I did was tighten up the drive belt (which seemed loose). I checked, and it is still level.

the next few times it came on it was okay, sounded normal. After about a half hour, it started again, first with "marbles" then "grinding gears". Finally, it just had a slight "marbles" sound to it.

Any Ideas?

right now we have it running with the power OFF and the sir control on the front of the door open, and the blower cabinet panel off to help with the hot air rising. on a positive note, if we only heated with oil, we'd be screwed right now! :D

BTW, for what its worth the furnace was bought new in august and installed by my brother in law, who went to college for hvac, but is pretty new to the game.

If anyone has a few free moments we could also chat on the phone to make it easier...

 

[JustWood]

Check to see if there is something inside the squirel cage. Once mine did this and I found a dead mouse in there which was throwing off the balance.

If there is nothing in there then it sounds like the bearings in the motor are bad.

 

[CowboyAndy]

also check if the squirrel cage is tight & not slipping

How do I check that?


Is it possible that the bearings could have gone bad after 2 months of use?

 

[Tony H]

You also mighrt want to check the direction of rotation of the motor and recheck the drive belt there should be 1/2 or more play in the middle of the belt , a tight belt will sometimes cause drag and noise you should be able to turn it by hand with everything off with some effort. One other item is to check and look for anything rubbing and look and see if there are grease zerks or oiler tubes to lube the bearings thay are not very common anymore but I am not familar with youe unit.

 

[CowboyAndy]

Well i'll be damned...


I took off the access panel, and looking right at me was the screw that holds the pulley on the blower. sittin right there on the ground. Put in the screw and its all good in the hood.