Dometic RM660 not cooling. Fix or replace?

jpares89 · 01-17-2014, 09:20 PM

I have an 83 21' fiver that I'm fixing to sell. It has the original Dometic RM660 3 way refrigerator in it. I think the fridge is junk. The 110v heating element trips the breaker once it gets hot, I haven't even tried to light the gas element. The 12v element gets real hot but the fridge does not seem to get cool at all. I would imagine all the ammonia leaked out.. Should I fix it or just throw a $50 mini fridge in it off craigslist? I'm thinking I just mini fridge it. A reman cooling unit is $350.. Thoughts?

**JohnB** · 01-18-2014, 01:13 PM

The electrical issue is not that hard to overcome. However the cooling coil is more involved. The 12 Volt element is more for "maintaining" than cooling the unit down. A feature that works well while driving.

The real question is the coil alright? Being it is unused for so long any traces of yellow residue of leaked out coolant may be long gone. Sitting so long it might be partial clogged inside. Or it rusted through and leaked out.

I myself have never worked through bringing a clogged one back to life. I have heard if you turn the fridge upside down it some times breaks free the clogs. Have to research how long you leave it turned over or how many times or do you shake it. The method may not be a factory certified method... however some have reported it working while others nothing. It is get lucky or not.

We had the 12 volt option on our PU. I always cooled the unit down on gas or 120vac and even then it takes a good 8 hours do feel it doing cool inside. Then flipped it over to 12 volt if needed while traveling which was not often. We used ice blocks to travel with.

The 120 vac unit tripping the breaker, odds are high it is shorting out when it gets hot. It expands creating a dead short. Assuming it is tripping a 15 amp breaker, the normal draw is no where near that much. Before you gas fire it, you need to really check and make sure the burner is all clean and not full of mud dauber nest.

Since your at, is it worth fixing or junk, if you want the use of boondocking with no power and run it on gas, then that benefit says try and see if the coil is good. If you are looking for spending close to nothing in $$ to find out, well clean up the gas system. It might fire right off. I did this on my son PU, was plugged shut with mud dauber but after cleaning it all up it fire right off.

If you get it to fire, do not leave the unit alone until you know it is safe. If the coolant is intact and flowable you should feel the pipes above the unit warming up after 20 to 30 minutes I would think. I can tell mine is working in a lot less time. If nothing is happening, pipes above unit are not getting warm with heat moving up the coil then take note it is not getting super red hot at the boiler area. I do not know the time period, maybe 60 to 90 plus minutes with a coil breach the boiler area gets dangerously hot. In worst cases wood around it can catch fire. This is the recall issues just I never heard how long it takes to get to critical mass and how close combustibles where.

And then there is, if nothings happening, try the rotate and flip and shake to see if you can break free the clog.

You are eating up time trying to sort it out, but if you get lucky you have a working fridge then buy a new 120 element. If you will never boondock off the grid, then a dorm fridge can be a solution. For us, we need the fridge to work on LP.

Good luck and let us know how this goes.

John

jpares89 · 01-19-2014, 07:27 AM

Thank you so much for all the information. I think ill just pull out the fridge and run it out side the camper to see if i can get it to work off gas. My other camper i use (32' newmar kountry star) sat for 5 years and has a electronic gas fired fridge as well as the 120v ac worked just fine no problems after all these years. The guy who gave me the sunline said it did work. so maybe the 12v element is not getting it to go. The coil is rusted but solid. Ill take it out and run it out side on lp.I will keep you all posted!

**JohnB** · 01-19-2014, 11:15 AM

Your welcome. Looking forward to the outcome. It is amazing some of these oldies can get back working again with some time, a little know how and well, luck..

**Sunline Fan** · 01-21-2014, 12:48 AM

I've yet to hear a success story of one being brought back to life, but it would be great to hear one! I believe the instructions were to leave it flipped over for about 24 hours, but maybe more time couldn't hurt? I have a printout of the instructions somewhere.

If you do scrap the refrigerator for a mini fridge, I'd slide the wood panel with pull handle out of the door face and tuck it inside the cabinet there, should someone want to put an RV unit back in there.

jpares89 · 01-28-2014, 09:13 PM

When I pull it out ill be happy to tell my story weather it's dead or alive.

jim44646 · 01-29-2014, 06:16 AM

Quote:

Originally Posted by Sunline Fan

I've yet to hear a success story of one being brought back to life, but it would be great to hear one! I believe the instructions were to leave it flipped over for about 24 hours, but maybe more time couldn't hurt? I have a printout of the instructions somewhere.
.

I had an old bought Space Age TT that was in storage for 10 years because of husbands death. The frig didn't work. I was going to pitch it when a friend told me to burp it. That said I pulled it from the unit and turned it on it's side for a day, then the top for a day, then on it's other side for a day then back upright. Fired it up and it worked. The gas burner was full of rust from the flu. I cleaned the flu and burner hooked a gas line to it, lit the burner. Low and behold in a few hours the frig was getting cold again. It was still working when I got rid of it.