Aux Coach Heater Repaired (Almost)

DancinCampers · 11-28-2006, 10:30 AM

Well, I have everything back together now, and after fixing a leaky hot water heater fitting it all seems good to go.

The heater now works on hi speed but not low. I'm not sure if it is the resistor pack in the heater housing or a relay. But that will have to wait for another day.

My sympton was the fuse would blow whenever I turned on the heater. Thought it might be a frozen bearing or melted fan blade. But it was neither. Turned out the squirrel cage had moved slightly toward the motor, and because the way it is manufactured, the squirrel cage was tight up against the motor housing. It was physically unable to turn. By holding the blades I tapped on the end of the shaft until I had it centered in the housing, and viola. Runs great.

My unit is located behind the water heater, so had to remove that first. Actually, the hardest part was separating the sealant between the lip and the coach. A windshield tool would have been nice. I used a putty knife, pliers and patience.

Here are pics of the heater:

Installed

End of fan enclosure

Fan in enclosure, notice resistor pack

Fan assembled, side view

Fan assembled, front view

Fan removed from housing

Fan end with spring

Fan end without spring. Notice the cone shape.

Heater mounting platform

Fan name plate

Now off to Disneyland

DancinCampers · 11-28-2006, 10:30 AM

Well, I have everything back together now, and after fixing a leaky hot water heater fitting it all seems good to go.

The heater now works on hi speed but not low. I'm not sure if it is the resistor pack in the heater housing or a relay. But that will have to wait for another day.

My sympton was the fuse would blow whenever I turned on the heater. Thought it might be a frozen bearing or melted fan blade. But it was neither. Turned out the squirrel cage had moved slightly toward the motor, and because the way it is manufactured, the squirrel cage was tight up against the motor housing. It was physically unable to turn. By holding the blades I tapped on the end of the shaft until I had it centered in the housing, and viola. Runs great.

My unit is located behind the water heater, so had to remove that first. Actually, the hardest part was separating the sealant between the lip and the coach. A windshield tool would have been nice. I used a putty knife, pliers and patience.

Here are pics of the heater:

Installed

End of fan enclosure

Fan in enclosure, notice resistor pack

Fan assembled, side view

Fan assembled, front view

Fan removed from housing

Fan end with spring

Fan end without spring. Notice the cone shape.

Heater mounting platform

Fan name plate

Now off to Disneyland

Sammie · 11-28-2006, 01:22 PM

Thanks for the information on your heater. I have had a similar problem with the heater on my 2000 Adventurer. From day one the fan motor when on makes a loud buzzing or scraping noise, so bad that I just don't use it. Now at least I have some knowledge on how to fix it. Did you have to disconnect the heater hoses to remove the water heater? or is there enough slack in the hoses to pull the water heater forward far enough to access the fan motor?

DancinCampers · 11-28-2006, 02:20 PM

Sammie,

I removed the 2 hoses to the aux heater (1 goes to the engine, the other to the HWH). Then I had to remove 1 hose from the HWH (the other hose was one that went to the aux heater & came out with the HWH).

I used 3 of those really fat super sharpie permanent marking pens to plug up the heater hoses. If your quick you won't lose much coolant. You will lose the amount in the aux heater & HWH.

Good luck.

troth · 11-29-2006, 06:17 AM

Dan:
1.)did you do anything with your brass check valves? (eliminate, or remove the guts?)
2.)your other thread showing the pic of the backside of the water heater... -you say there is a resettable ECO, but I don't see the reset button. link to other pic
3.) How far out can the water heater be moved from the cabinet before the propane line has to be disconnected? Did you remove your water pump and/or the white fiberboard vertical "wall" next to the water heater first?

DancinCampers · 11-29-2006, 07:30 AM

troth,

I didn't do anything with the check valves. They work fine & was in a time crunch to get the aux coach heater fixed.

It is hard to see the reset button, it is the same color as the back of the ECO. It is rectangular in shape, located between the terminals.

There really is no slack in the gas line. Took it off first. I removed the output connection from the water pump & placed it on the top shelf (that goes under the slide arm). Unscrewed the plumbing from the white board & removed the board. It is tricky, you need to pull the drain tube out of the floor & then move the plumbing to the left. I had to remove the gasket from the compartment lip to get it out on an angle. The board is quite thick, & on mine at least, I had to remove the 2 lower left screws that hold in the HWH, as they went into the board.

I had the board out previously, so I had already modified the compartment light wires, adding butt connectors.

With the board removed there is enough room above the HWH to put your arm over it to remove the rear water fitting on the Hot side. The cold side is also easy to get to.

I modified the board this time, making it easier to see the hot side connector & reset the ECO. I want to keep an eye on any leaks until I'm comfortable. The plumbing is very stiff, & the first time I connected the hot side it leaked because the washer had gotten crimped because the pipe did not go in straight but at a slight angle. No leaks as of yesterday.

Here is the before & after mod to the board.

troth · 11-29-2006, 08:09 AM

Excellent (again!) Dan. Thanks so much for the detail and pics.

DonavonP · 11-29-2006, 12:07 PM

Thank you from me too Dan. Great write up and pictures.

tderonne · 07-14-2010, 03:16 PM

Finally getting around to working on my noisy aux heater fan. I can get at it, but I don't see how to remove it yet. Sounds like I have to remove the whole enclosure it's in? Not just the motor? I need to look at it some more, and do some more searching here...

Any chance the pictures in this thread still exist? Maybe at a new address?

tderonne · 07-14-2010, 07:14 PM

Got it out.

Couldn't get the whole housing out, but able to move it around enough to unbolt the fan.

I'm not sure what to do from here. I can move the cage around on the shaft, but the shaft also moves in the motor. I may just put it all back together and hope I get six more years out of it.

I've been reading old threads. I see new assemblies have been installed, cages repositioned, and some epoxying. Not sure I've seen a definitive fix....

InPursuit · 07-14-2010, 07:37 PM

my atwood heater seems to only have one speed (high).

I haven't dived into the manual yet (I'll wait til fall) but...
do the plain vanilla FHA furnace motors have a two or variable speed option?

Thanks

DancinCampers · 07-15-2010, 06:38 AM

Tim, I am sorry, but like the perfect storm, I lost all my files.

The problem on mine was the cage, over time, migrated along the shaft, toward the motor. Eventually, the motor casing rubbed the inside of the cage. It finally got to the point where it jammed, and would blow the fuse each time I turned on the switch.

I fixed it by moving the cage away from the motor so it would not rub, installed 2 very small screws in the end of the cage in place of the spring, then used putty epoxy and molded a piece so that it covered both the screws and the end of the shaft.

It is still working today.

Hope this helps.