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Topic: Gas furnace  (Read 468 times) previous topic - next topic

Gas furnace

The front furnace makes a whistling noisy on the outside of the coach. The rear one does not. Any remedy?
Rick and Julie
Grand Villa
Build #4689
1995 4000 U280SE WTBI
8.3L 300HP Cummins

Re: Gas furnace

Reply #1 –
probably time to replace the motor. check the number on the motor,
not a big job.  you tube can help.

Re: Gas furnace

Reply #3 –
Thanks Chuck!
Rick and Julie
Grand Villa
Build #4689
1995 4000 U280SE WTBI
8.3L 300HP Cummins

Re: Gas furnace

Reply #4 –
Sorry I couldn't be more helpful (besides linking the furnace manual).

I went through the rebuilding of both our furnaces not long after we bought our coach.  Over a period of time, I eventually replaced the motors, burner tubes and ignitors in both of them.  However, I never had the same kind of sound you are describing, so not sure what to suggest.  It could be the motor (dry bearings) as suggested above.  There are a good number of threads on the Forum dealing with working on the furnace.  The one linked below includes some comments by myself and Ken from when we were both having "furnace problems".  May be of some help as you do your trouble shooting.

Need Hydro Flame Furnace Burner


1993 U280 SE 40' WTBI, Build: 4359
C8.3 300hp, 6-Speed, Exhaust Brake
960 watts on the roof (6 x 160)
Sorento (or BOLT) on a Kar Kaddy SS
"Nature abhors a vacuum"

Re: Gas furnace

Reply #5 –
The motor bearings (bushings) can make some strange noises.

While motor replacement is the correct long-term solution, in many cases you can add a few drops of non-detergent light oil (sewing machine oil works well) on the shaft just outside the motor.

Use  long screwdriver or other tool to deposit the oil on the shaft.
Brett Wolfe
EX: 1993 U240
Moderator, ForeForum 2001-
Moderator Diesel RV Club 2002-
Moderator, FMCA Forum 2009-2020
Chairman FMCA Technical Advisory Committee 2011-2020

Re: Gas furnace

Reply #6 –
Quote from: wolfe10 –
...you can add a few drops of non-detergent light oil (sewing machine oil works well) on the shaft just outside the motor.
Use  long screwdriver or other tool to deposit the oil on the shaft.
The Zoom Spout oiler also works well for this purpose.  I have several bottles scattered around my shop.  Good stuff!  :thumbsup:

https://www.homedepot.com/p/DIAL-4-oz-Evaporative-Cooler-Zoom-Spout-Oil-5714/100128593

1993 U280 SE 40' WTBI, Build: 4359
C8.3 300hp, 6-Speed, Exhaust Brake
960 watts on the roof (6 x 160)
Sorento (or BOLT) on a Kar Kaddy SS
"Nature abhors a vacuum"

Re: Gas furnace

Reply #7 –
Oil the motor on both ends of shaft. Also look for stuff in the squirrel cage blower
 

Re: Gas furnace

Reply #8 –
Both motors are probably the same get both now and be done with it,oiling works but only temp fix.
96 U270 BUILD 4810
85 380SL
Drummonds TN.