Go Back   iRV2 Forums > RV SYSTEMS AND TECHNOLOGIES FORUMS > RV Systems & Appliances
Join iRV2 Today

Mission Statement: Supporting thoughtful exchange of knowledge, values and experience among RV enthusiasts.
Reply
  This discussion is proudly sponsored by:
Please support our sponsors and let them know you heard about their products on iRV2
 
Thread Tools Search this Thread Display Modes
 
Old 02-08-2011, 12:15 PM   #1
Junior Member
 
geofferyh's Avatar
 
Join Date: Feb 2011
Posts: 6
Question Atwood Furnace Squealing Noise

My Atwood 8535 IV furnace is making an intermittent squealing noise of varying pitch and amplitude, blower rotation actually seems quiet, it is more like a high pitched vibration as versus rotation noise. This high pitched squeal typically occurs shortly after the blower start running, or sometimes after it has run for awhile. The longer the blower is running the more likely the squealing is to stop. This is why I have pretty much eliminated blower motor rotation as the source. I can't see anything in the fan blades and I have a mud dubber screen on the exhaust.

Any ideas would be greatly appreciated before I start taking things apart.
__________________

__________________
geofferyh is offline   Reply With Quote
Join the #1 RV Forum Today - It's Totally Free!

iRV2.com RV Community - Are you about to start a new improvement on your RV or need some help with some maintenance? Do you need advice on what products to buy? Or maybe you can give others some advice? No matter where you fit in you'll find that iRV2 is a great community to join. Best of all it's totally FREE!

You are currently viewing our boards as a guest so you have limited access to our community. Please take the time to register and you will gain a lot of great new features including; the ability to participate in discussions, network with other RV owners, see fewer ads, upload photographs, create an RV blog, send private messages and so much, much more!

Old 02-08-2011, 12:43 PM   #2
Senior Member
 
WSRG's Avatar


 
National RV Owners Club
Workhorse Chassis Owner
Join Date: Dec 2008
Posts: 182
It's almost always the blower bearings that make the squealing noise that you are describing. It is possible to lube the bearings by removing the outside cover to expose the blower motor. The only way to lube them without having to disassemble the blower assembly, is to use a good quality squirt type oil [not WD-40] with a long tube to reach the bearings. Try not to get too much oil on the squirrel cage during this process.
Lubing the blower motor is only a temporary fix, since the squealing noise means that the bearings are already worn out. Hearing this noise almost always means that a blower motor replacement is in your future.

Bill
__________________

__________________
BILL & CINDA SCHWARTZ
2005 SEABREEZE LX 8360
BEAUTIFUL PHOENIX, AZ
WSRG is offline   Reply With Quote
Old 02-08-2011, 01:29 PM   #3
Junior Member
 
geofferyh's Avatar
 
Join Date: Feb 2011
Posts: 6
Atwood Furnace Squealing Noise

Quote:
Originally Posted by WSRG View Post
It's almost always the blower bearings that make the squealing noise that you are describing. It is possible to lube the bearings by removing the outside cover to expose the blower motor. The only way to lube them without having to disassemble the blower assembly, is to use a good quality squirt type oil [not WD-40] with a long tube to reach the bearings. Try not to get too much oil on the squirrel cage during this process.
Lubing the blower motor is only a temporary fix, since the squealing noise means that the bearings are already worn out. Hearing this noise almost always means that a blower motor replacement is in your future.

Bill
I'm not so sure about that Bill. Recall that the noise is more of a metalic vibration squeal rather than a rotating motor dry bearing rasping sound. A new development has now surfaced.

I have checked and found no obstructions or debris within the area of either cage fan. I removed the Draft Cap Assembly and found two metal pieces that look like parts of some kind of circular spring clip. See attachment.
Attached Thumbnails
Click image for larger version

Name:	Metal Pieces.jpg
Views:	104
Size:	180.4 KB
ID:	8224  
__________________
geofferyh is offline   Reply With Quote
Old 02-08-2011, 11:17 PM   #4
Senior Member
 
WSRG's Avatar


 
National RV Owners Club
Workhorse Chassis Owner
Join Date: Dec 2008
Posts: 182
It's hard to make out what that part is. I don't have any reference to compare it's size. It may be a ring clip that goes around the hub of the combustion wheel to keep it tight on the motor shaft. It is also possible that it may be a part that was just left inside the furnace when the furnace was built or installed in your coach.

Let me know what you figure out.

Bill
__________________
BILL & CINDA SCHWARTZ
2005 SEABREEZE LX 8360
BEAUTIFUL PHOENIX, AZ
WSRG is offline   Reply With Quote
Old 02-09-2011, 12:29 AM   #5
Junior Member
 
geofferyh's Avatar
 
Join Date: Feb 2011
Posts: 6
I talked to the factory tech on the phone this afternoon. There is supposed to be a ring clip around the hub of the combustion wheel.

Mine is missing. Therefore, it is my belief that the metal pieces are what's left of the ring clip. It apparently broke off and made its way through the combustion chamber to the exhaust port. The wheel is still firmly in place. Should probably get another ring clip though.

I still think the squealing noise is vibration related, even though the Atwood Tech thinks I may have a motor bearing that is going bad. In that this is an intermittent problem, I don't see how it could be a motor bearing. I adjusted the Draft Cap Assembly for a tighter fit and better alignment. It has the only metal to metal fit in the combustion chamber area. I'll know more tonight when the furnace is in use again.
__________________
geofferyh is offline   Reply With Quote
Old 02-09-2011, 07:02 AM   #6
Senior Member
 
WSRG's Avatar


 
National RV Owners Club
Workhorse Chassis Owner
Join Date: Dec 2008
Posts: 182
Keep in mind that the bearings on the blower motor are bronze oillite bearings and not ball bearings. They can make all kinds of different noises, ranging from a squealing to a rumbling noise when they go bad.

Also, did you check to make sure that both the cumbustion wheel as well as the blower wheel are turning true inside both of their cages. Either of these wheels could be bent slightly...causing an out of balance condition that would put extra strain on the bearings.

Bill
__________________
BILL & CINDA SCHWARTZ
2005 SEABREEZE LX 8360
BEAUTIFUL PHOENIX, AZ
WSRG is offline   Reply With Quote
Old 02-09-2011, 08:31 AM   #7
Senior Member
 
Join Date: Feb 2011
Location: Oregon
Posts: 209
Read hundreds of furnace squeal threads over the yrs and every one of them has been blower related.

The blower motor is easily accessible when you remove the exterior shield. You might consider starting up the furnace with the exterior shield lowered - probably hear/feel the squeal coming directly from the motor.

Replacing the motor on a 8500 series furnace isn't very hard and you don't have to removal the furnace.
__________________
ksg5000 is offline   Reply With Quote
Old 02-09-2011, 10:35 AM   #8
Junior Member
 
geofferyh's Avatar
 
Join Date: Feb 2011
Posts: 6
You guys make good points.

Since the metal parts found are now known to be from the combustion side wheel hub ring clip, I was planning on checking the wheel alignment next. Also, since all the material associated with the broken ring clip has not been found as yet, I am going to blow HP air around and through the wheel vanes just in case that material might be associated with the squeal. I should be able to get any remaining debris to exit via the exhaust port.
__________________
geofferyh is offline   Reply With Quote
Old 02-09-2011, 04:34 PM   #9
Junior Member
 
geofferyh's Avatar
 
Join Date: Feb 2011
Posts: 6
Post Fixed the Atwood Furnace Squeal

I finally solved the "Squeal" problem and it was not a motor bearing. Hey, when was the last time I have seen a light duty motor with bronze bearings wear out with only maybe a years worth of run time. Duh, almost never. However, I suspect many motors have been replaced over what should have been a truly simple fix.

Remember, the metal retaining clip ring around the hub of the exhaust wheel cage fan broke. This allowed the wheel to migrate inward to begin minor contact with the plastic housing. Plastic housing + Plastic Wheel = "Squeal".

Moved the wheel back out about 1/32" and replaced the ring clip with one that I got from the NAPA Auto Parts store. (The RV supply store sells the clip, but only with a replacement wheel for $25!).

Hope this helps someone else.
__________________
Jeffery
2003 Holiday Rambler Admiral SE
Summer in N. Michigan, Winter in Gold Canyon, AZ
geofferyh is offline   Reply With Quote
Old 02-11-2011, 12:32 PM   #10
Senior Member
 
SpursMVP's Avatar
 
Monaco Owners Club
Join Date: Jul 2010
Location: O'Neill, Nebraska
Posts: 345
We seem to be having the same problem. It's not a squeal, but rather a rattle.

Took off the cover and observed/listened and the motor seems to be running very smoothly. Checked the retainer clip on the end of the shaft the wheel is on...it was on snuggly.

Are there any other parts that could rattle? I've checked all the screws and all are tight.
__________________
2001 Holiday Rambler Endeavor
330 HP Cummins ISC
2007 Dodge Ram 4 X 4 (Hemi)
SpursMVP is offline   Reply With Quote
Old 02-18-2011, 07:31 PM   #11
Senior Member
 
Join Date: Feb 2011
Posts: 132
I fixed same problem about 6 months ago. Wish I had read thread sooner, could have saved you time.
__________________

__________________
Its Paid For is offline   Reply With Quote
Reply



Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Atwood Furnace infinity1 RV Systems & Appliances 14 05-14-2013 09:20 AM
atwood furnace model 8535 ran out of propane, won't restart now rewaters49 RV Systems & Appliances 6 12-15-2010 08:21 AM
Atwood & Suburban water heaters & Furnace "007" RV Systems & Appliances 1 08-07-2010 10:37 PM
Atwood furnace problem clintstimson RV Systems & Appliances 9 03-23-2010 04:14 AM
No spark in Atwood furnace gg RV Systems & Appliances 1 01-14-2010 06:14 PM


All times are GMT -6. The time now is 03:19 PM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2014, vBulletin Solutions, Inc.