Dometic RM211 Fridge Repair

[babyblue]

Hello:

I will start doing some troubleshooting to try to repair my Dometic RM211 and see if I can bring it back to life.

Is it possible that the problem can be the water, ammonia, hydrogen mixture needs to be replaced? It sat in a garage for 11 years unused and hasn't worked since. Just wondering if that might be something that I can get replaced?

I plan on first cleaning it really well, then glueing the inner liner back together as it is ripped, and then will test the electrical to see if any of it works. Any tips greatly appreciated!

[David Tilston]

Anna, If the cooling system has developed a leak, then it is likely not worth fixing. The leak would have to be fixed first. I'm told that the heated section of the cooling circuit is where most of the corrosion happens. Joe Thoen at Trillium / Outback has experience repairing the cooling circuit on absorption refrigerators. He told me that cutting out the heated section and welding in a new pipe is the first step. Refilling the required ammonia, hydrogen and water would be done after that. How much of each????

Why do you think it is broken? The tests that I would do to determine if it works would involve plugging it in and confirming that there is about 1 Amp flowing through the heater at 120 VAC. Or, before you plug it in measure the resistance of the 120 VAC heater. It should be about 150 ohms. If no current is present, (or the resistance is infinite) then the 120 VAC heater is probably dead. This is frequently the problem. The 120 VAC heater is most commonly used and wears out first. I would then try the DC heater. This is not as commonly used and it is probably OK. You should see about 8 amps on the DC heater, or about 1.5 ohms of resistance. You will need a source of 12 VDC. I would use a battery, connected to a battery charger. Give it a couple of hours, with the door closed. If the freezer is not cold after that, then the cooling circuit is probably dead.

However, replacement RM211’s are not too difficult to find. I have a couple of spares. They were very common in pop up tent trailers. Watch in the used trailer parts section of Craig’s List, or Facebook, or whatever your favorite used shopping method is. The target price I would shoot for is $100. But if the price is higher in your area, then you might end up paying closer to $200. When you go to look at it, have the seller plug it in 24 hrs before you get there. Be sure to test the resistance of the heaters, (when there is no voltage) before you buy.

Lastly, even if your fridge is not worth fixing, it may be worth pulling off all the parts that are still good. Like the heater. To get this out intact, cut out all the insulation that is under the access door for the heater. Get a pair of needle nose plyers and pull the heater tube, not the wire. Pulling the wire could result in a dead heater. Ask me how I know. Also of value are both the thermostats, the selector switch for the three modes, all the gas components right up to the burner, all the shelves inside the fridge… you get the idea, (I may be a bit of a pack rat)

[babyblue]

Thank you as always, David! I’ll start on it next week and let you know!

[Friz]

Having lived with a RM211 for 15 years, I found that the gas jet was usually clogged. Do not drill it out or force wire through it. A spray can of brake cleaner will do the job. Remove the jet before doing this, brake cleaner is flammable & bad for the eyes.

If the fridge has an ammonia leak and you junk it out, hang onto this jet also. They were over $40 a few years ago, no telling how much now. Also the door and hinges.

[Borden]

3 way fridge so try 120v first and then propane. if one works different problem.
We had to have the regulator at front changed about 8 years ago. After we had to have a trailer gas specialist adjust the regulator to give the correct volume for running all; our hot water tank, 4 burner oven, furnace and fridge to all work properly at once. Prior the fridge did not get cold on propane.

Note: we have to always start all the burners on the stove first before starting the fridges pilot and then it still takes a moment to get the furnace and fridge to get gas.

If propane works but not 120v then the 120v heater not working.

12v is only for travel and we always first use 120v or propane to get it cold first then switch over as it is a power hog. Works well while on the road but will drain the battery fast at site. It has a 10amp fuse that can go.

Would try this before pulling things apart. We usually do not have a meter while at the camp site as we load light. Fuses have been a problem in the past.

Hope this is of help.

[Borden]

Originally Posted by David Tilston

Anna, If the cooling system has developed a leak, then it is likely not worth fixing. The leak would have to be fixed first. I'm told that the heated section of the cooling circuit is where most of the corrosion happens. Joe Thoen at Trillium / Outback has experience repairing the cooling circuit on absorption refrigerators. He told me that cutting out the heated section and welding in a new pipe is the first step. Refilling the required ammonia, hydrogen and water would be done after that. How much of each????

Why do you think it is broken? The tests that I would do to determine if it works would involve plugging it in and confirming that there is about 1 Amp flowing through the heater at 120 VAC. Or, before you plug it in measure the resistance of the 120 VAC heater. It should be about 150 ohms. If no current is present, (or the resistance is infinite) then the 120 VAC heater is probably dead. This is frequently the problem. The 120 VAC heater is most commonly used and wears out first. I would then try the DC heater. This is not as commonly used and it is probably OK. You should see about 8 amps on the DC heater, or about 1.5 ohms of resistance. You will need a source of 12 VDC. I would use a battery, connected to a battery charger. Give it a couple of hours, with the door closed. If the freezer is not cold after that, then the cooling circuit is probably dead.

However, replacement RM211’s are not too difficult to find. I have a couple of spares. They were very common in pop up tent trailers. Watch in the used trailer parts section of Craig’s List, or Facebook, or whatever your favorite used shopping method is. The target price I would shoot for is $100. But if the price is higher in your area, then you might end up paying closer to $200. When you go to look at it, have the seller plug it in 24 hrs before you get there. Be sure to test the resistance of the heaters, (when there is no voltage) before you buy.

Lastly, even if your fridge is not worth fixing, it may be worth pulling off all the parts that are still good. Like the heater. To get this out intact, cut out all the insulation that is under the access door for the heater. Get a pair of needle nose plyers and pull the heater tube, not the wire. Pulling the wire could result in a dead heater. Ask me how I know. Also of value are both the thermostats, the selector switch for the three modes, all the gas components right up to the burner, all the shelves inside the fridge… you get the idea, (I may be a bit of a pack rat)

Great advice

[Borden]

Originally Posted by Friz

Having lived with a RM211 for 15 years, I found that the gas jet was usually clogged. Do not drill it out or force wire through it. A spray can of brake cleaner will do the job. Remove the jet before doing this, brake cleaner is flammable & bad for the eyes.

If the fridge has an ammonia leak and you junk it out, hang onto this jet also. They were over $40 a few years ago, no telling how much now. Also the door and hinges.

Will have to learn more about this for future should we ever have a problem.

[gordon2]

Originally Posted by Borden

Will have to learn more about this for future should we ever have a problem.

If you want to learn more about it then you could always read the friendly manual (AKA RTFM):
https://fourwheelcampers.com/NewDome...atorManual.pdf.
Cleaning the burner is described on page 20. Brake cleaner might work (or might be a bad idea - IDK).. the manual says to soak it in an alcohol based solvent and does not mention brake cleaner.

[Borden]

Originally Posted by gordon2

If you want to learn more about it then you could always read the friendly manual (AKA RTFM):
https://fourwheelcampers.com/NewDome...atorManual.pdf.
Cleaning the burner is described on page 20. Brake cleaner might work (or might be a bad idea - IDK).. the manual says to soak it in an alcohol based solvent and does not mention brake cleaner.

Thankyou our RM36 fridge manual does not say how to fix it. Saved it will be a great resource. General layout is same. We had ours serviced when we added the new gas regulator at the front 8 years ago but things happen while camping.