Community Forums

Toby · 08-18-2006, 12:54 PM

I have 13T BTU heat pump by Duo-Therm on my 2004 MH. Sometimes the fan sticks which prevents the A/C from working. I get up on the roof and remove the cover and give the fan a whirl and it works fine after that. Does anyone know if there is a place to oil the fan shaft? or get it to quit sticking/ s/Toby

Toby · 08-18-2006, 12:54 PM

I have 13T BTU heat pump by Duo-Therm on my 2004 MH. Sometimes the fan sticks which prevents the A/C from working. I get up on the roof and remove the cover and give the fan a whirl and it works fine after that. Does anyone know if there is a place to oil the fan shaft? or get it to quit sticking/ s/Toby

Ed Gardiser · 08-18-2006, 02:20 PM

Toby
Try replacing the run capacitor for the fan motor.
Ed Gardiser
Escondido,Ca.
04 Vectra
87 Nissan PickUp
FMCA

Cruzer · 08-18-2006, 02:57 PM

Toby, there were a bunch of bad fan motors on DuoTherms about that time. Call your dealer, there was a service bulletin out on those units and they are covered under the three year Dometic warranty. I had one of mine do the same this spring and my dealer fixed it all up. You will need to remove the inside air filter and look for the model nbr, serial nbr, and spec or type nbr. Your dealer will ask you to get those for him.

Toby · 08-19-2006, 03:41 PM

Ed & Cruzer Thanks for the info. For some reason, I don't have any warranty papers on the two heat pumps like all the other gizmos in the MH. I was hoping that there was a zerk fitting that I could grease. Didn't know about the 3 years warranty. I'll check that out. s/Toby

cherokee37g · 07-27-2011, 05:38 PM

I need to resurrect this 5 year-old post because I am having the same problem with a 2004 unit and the original question really wasn't answered.

Just as in the original post, my fan sometimes needs a little help to get it spinning which involves getting up on the roof and removing the cover to spin the fan. After that it works fine. I don't suspect the run capacitor needs to be replaced. It seems to be a problem of the shaft being "gunked up" with old grease. Of course I can "un-gunk" it but that leaves me with the original question....

My understanding is the appropriate lubricant to use is something like Liquid Wrench rather than WD40. Any expert opinions on that? It would seems just squirting some oil on the shaft where it comes out of the motor housing is the way to go. Yes?

Thanks!!!!

Steve

TXiceman · 07-27-2011, 06:14 PM

Dometic has had a continuing problem with the shaft of fan motor rusting in the bearing. Unless you start and tun the fan motor for about 15 minutes every 3 or 4 weeks, it will be a problem. I even tried coating the exposed shaft with a heavy grease. It helped a little, but did not cure the problem. I guess the motors they buy have really poor quality steel in the shaft.

If it is not sticking, it could be a start capacitor problem.

WD40 should never be used as a lubricant nor should Liquid Wrench. After using these, you need to apply a good oil...standard 30 wt motor oil will work.

You do not need to remove the cover to just free it up. Use a stick to push the fan blade from the side vents.

Ken

cherokee37g · 07-27-2011, 06:34 PM

Great, thanks for the quick reply, Ken! Sounds like I'll have continued problems then. So no liquid wrench either, huh? Ok, I'll use the 30 wt oil. That was really my question, what type of oil is best.
I'm sure I'll work something out with a stick or bent up coat hanger to push the fan thru the vents like you said. Then maybe I can reach it from a ladder without having to get on the roof. Probably stick with that routine until I break down and just replace the whole unit.

Thanks again!

Steve

Shore2Shore · 07-28-2011, 04:52 PM

From internet searching the same question regarding what to lube a/c fan motors with most if not all said 30 weight oil. Our original Coleman top unit that worked eventually needed help in getting the fan to spin.

We could reach ours by taking the ceiling unit cover off and actually spin the fan to get it going. In the end the problem that was causing ours not to spin without help was worn bearings & rust.

cherokee37g · 07-28-2011, 05:14 PM

I wondered if I'd be able to poke at the fan from inside the ceiling cover. I'll have to check and hope I can reach it because that's so much better than climbing up there.
Hopefully that works until I can find a replacement motor.

steve

hometool · 07-28-2011, 05:21 PM

hi i have tryed many times to freeup those small fan motors with very little sucsess the only real cure i have found is a new motor if your return air is right below the unit you probably can remove the filter and access the fan blade that way lee

cherokee37g · 07-28-2011, 06:02 PM

Well, right now I'm only at the point where the fan just needs a little push to get it going....and that's only if it hasn't been run for a few weeks. I'll try some oil to maybe buy some time but sounds like things will only get worse in the future. Since I'm confident I'll be able to do a motor replacement myself I'll start looking for a new motor now and hope it holds out til I get one.

jsyl · 07-29-2011, 09:23 AM

I have a 2004 navigator with 3 Duo-Therm heat pumps and the front one was hanging up and needed a push now and then. After the second push I checked the capacitor which was fine. These motors have sealed sleeve bearings that cannot be lubricated unless you dissemble the motor ends. Lubrication was not problem, it was rust on the armature and the stator of the motor. After removing the rust the motor ran great. How i found the problem was when I spun the shaft I could hear a faint rubbing sound which indicated there was an internal problem. The rust was enough to break the field when ever it stopped in certain positions. Be very careful when dissembling your motor if you do it yourself that you remember how to put it back together and you don't loose any of the shaft spacers. Removing the motor from the unit can be a real challenge if you have never done it before. If you would like a new motor kit, The best price that i found was at American RV Company in Azusa California 626-513-4777, it comes complete with new capacitor, support brackets and instructions on removal and installation. The current cost is $120.95 plus shipping. I just bought one to have as a backup in case one of the other ones start acting up while we are on the road. We will be departing at the end of August on a seven thousand plus mile trip and I really like having A/c. Good luck

TXiceman · 07-29-2011, 04:09 PM

Like I said, Dometic has had this problem for a number of years and has done nothing about it. That is why I tell people to replace their A/C units with a Coleman.

Ken