Dometic Refrigerator TIPS on Propane

[Ray Eklund]

This is meant for effective Off the Grid Boondocking. RV Parks are a totally different and much easier once plugged into Power. OTG you depend on efficient Propane operation. We do and the Propane Use is very little in comparison to a Furnace running to have your 'tootsies' warm. Wear socks and add more covers at elevation when it gets below Freezing. We survive every year. You might.

So much disinformation of Refers... it makes me want to cough up a fly I swallowed earlier in the day by accident. But I won't. This inspired me to open Pandora's Refer Tips for REFER MADNESS. Be patient. I tried to cover everything that may be questioned when putting this together.

We had a 2006 23 foot Safari. Had the Microwave we never used. We ended up with the Cooling Fans for the Dometic Refrigerator. Eight years of trying to keep the Refer cooling. Lucky for us we had a 60 watt factory Solar Panel that kept the batteries from being COLD Dead. Limped along for 8 years. Needed to replace fans, often as they became noisy.

We sold the 2006. Bought a 2014 25 foot International. It had the two fans and microwave. The only 25 footer available. Same issues as above. Learned my lesson. Bought a portable Costco Solar Panel to keep the Battery from becoming COLD and a Lead Anchor. But... survived and manage to keep things running.

Sold the 2014 and and bought a 2019 27 foot International Without the Microwave and added two Factory 80 watt Solar Panels on the Roof and a 100 watt Costco portable. Happy, happy, and happy. Refer on Propane is wonderful and NO NOISY FANS. The 27 foot exhausts HEAT through the ROOF. No FANS. Yaaa Hooo. Took two Airstreams to figure out they were not the same Systems. Now, I do.

There is a "System to the Madness" of getting your Dometic down to temperature before departing on a Boondocking Adventure. We have ours parked in our RV Garage at home. We plug the trailer into home power. That is convenient for us, not you.

Nancy’s Refer Madness Learning Curve Cooling

1- Plugged in home power, it takes ONE to TWO Days cooling the Dometic Down. It is set at Maximum FIVE out of FIVE on the cooling setting. Cooler months one day. Hot months give it two days. When it gets to 37- 38F in the refrigerator, 5-8F in the Freezer.

I will put a Floor Fan that blows into the side of the trailer towards the ‘trap door’ where the flame is located. The fan blows heat away and the Refer becomes MORE EFFICIENT IN ITS COOLING.

2- Once down to temperature she begins to LOAD the refrigerater and the Freezer (Ice Box to some, where you store Ice Cubes to a Neanderthal). The food is removed from OUR Home Refer and Ice Box. That is important.

3- Once loaded she sets the cooling according to the temperature in the garage either 3 or 4. You do not want to freeze the entire Refer. It is already operating well. We will leave the Refer plugged into home power the afternoon before we leave on our trip.

4- (I have already bled the Propane System from furnance, hot water tank, cook top and ready to fire up the Refer Propane System.) It will try to ignite. It may right away or not. If not, try to ignite again and it will 100% of the time. Sometimes on the first try. Always on the second try.

5- Once we are on the road, traveling the Refer is set at 3, but if the outside temperatures are HOT... 4. When I stop for Fuel, Nancy checks the interior temperature. Too cold, down to 3, not cool enough left on 4. Every fuel stop, she checks the temperatures.

6- By this time YOU now know and undertand you monitor the system and try to maintain a temperature you want. You do not want to freeze your food in the Refer, but keep the Refer at (37-38F) and in the Ice Box (5-8F). You find your sweet spot. This is hers.

7- Once camped I take a dowl stick and hold the lower vent cover OPEN to keep ventilating and getting the heat to rise out of the roof vent. It will help a few degrees in the Refer and Ice Box. Adjust as needed. We are usually at 3. Hot day maybe 4, reduce at night to 3. ...and so on.

8- The Dometic Refer Tango is now your Dance. It is very efficient and we have never had one problem with the Ammonia or Ignition. You can hear it POP and the flame when inside and easily outside.

If you have a question that I cannot answer, I will ask Nancy. The Interior is her responsibility and I maintain everything and the outside operation. You can do the same if you like. It works well for US. Nancy is a Human Bean. I am still a Neanderthal, but working on my Beanness...
******
This was as short as I could manage. It is an excellent process used by us for 15 years, but the Roof Top Vent system is our current and the BETTER. The Fans were noisy, unreliable even when I used a dowl on the vent door to help cooling the system to become more Efficient.

It is the most important, to us, of all the Propane appliances. Next is the cook top. We rarely use the furnace at 25F outside and 35 inside. Add lots of covers and orientate the Trailer for maximum Sunrise striking side of trailer... this is discussed somewhere else on Boondocking in a Thread.

Feel free to comment or ask questions. Print a copy and come up with questions. This sounds easy... until you try to figure it out. We have 15 year of fixing, adapting and cursing... but I have all ten fingers and still handsome enough to keep a good wife happy and two Blue Heelers. The Airstream is the BEST CAVE I have lived!

[Ray Eklund]

When you are traveling and moving on the dirt road or highways... the wind is actually making your Refer System work more efficiently. It is cooling down the Ammonia Lines and making your Refer remain closer to the temperatures you prefer.

If you put a filter on the inside of the exterior vent cover to keep dust out... you will prevent the wind from assisting your Refer to be efficient. You will clog up the filter and then your REFER will warm up and your Frozen Hot Dogs may hatch into full sized Blue Heelers. Imagine that? I do. We have Two Blue Heelers now.

Once you set up camp. Prop the vent cover at the bottom open with a 12 to14 inch dowl to help the system cool better.

A Brain is a terrible thing not to use.

That is why I work better using my Hands. More efficient for me and my fingers do the thinking and typing while I daydream of this new OTG Boondocking Adventure into the High Country of Utah, Colorado and Wyoming.

Yaaa Hooo and it is Cool once you are camped over 6,500 feet elevation.

[Justin J]

That’s a great write up Ray. I’d add don’t pack the refrigerator wall to wall. Since cold air falls and heat rises. This maximizes the cooling effect of the evaporator type system.

[field & stream]

Wonderful write-up, and thanks. You made my day with “refer madness”!

We traveled the same path you did starting with a 2008 23’ Safari SE. Added fans help, but the lack of a chimney is a grand design error which we still have to work around with our 16’.

After 15 years our Dometic propane fridge is failing and after wrestling with the pros and cons and bucks of electric only compressor fridges we have decided to replace the propane fridge. Seems to us (with adequate solar and battery) it is just a better solution for the unplugged.

Tip: putting ice in the fridge can shorten the cool down time significantly.

[ITSNO60]

The roof vent is definitely the best way to vent the absorption fridge but if you are stuck with 2 side vents there are things you can do to improve air flow. The installers don't read the installation requirements.
1 1" or less clearance to back wall, this is important to direct the convected air through the coils and fins instead of bypassing them. Mine was 2", solution is a baffle, or better yet, pull fridge and add foil backed foam board to back wall to reduce clearance to 1" or less.
2 Next is the cavity above the fridge which is a square box and often extends up past the top vent. The convected air gets confused and trapped here and does not smoothly flow out of the top vent. Some thin aluminum sheet made from 4" dryer vent material curved to make a smooth path for the air to keep moving helps a lot, and takes away the square corner where it gets trapped.
3 The fans, Dometic puts one noisy one under the condensers, I changed mine to 2 high quality quiet computer fans. Keep them on the snap disc control, you don't want them on all the time as overcooling the condensers will have a negative effect on the absorption process.
4 1 or 2 exhaust fans at the top vent can help, these should also be thermostatically controlled. I chose to install a Fridge Defend with an auxiliary, thermostatically controlled fan option. I did not use their fans but instead used 2-200mm (8 inch) slow RPM computer case fans. I wanted a slow, gentle boost for the airflow, nothing too crazy that would cause back pressure at the vent and confuse the smooth, steady convection. The 8" computer fans also do not block the natural flow when off. I have mine tilted upwards at the bottom to direct the air out the holes in the vent which leaves more space for natural convection when they are off.
5 The flue pipe, many installers leave the flue pipe to vent inside the fridge cavity where it dumps hot exhaust out right under the condensers. The Dometic installation instructions state, in every case, to vent the flue to the outside using a flue gas extractor kit, no where do they say it is OK to let the flue vent inside the fridge cavity, yet installers do it. The extractor kits are available on eBay for $30 and easy to install.
All this helps make a side vent better, but never as good as a roof vent. Most of what I did was not really a mod, it was correcting an improper installation. The only mod part was the Fridge Defend and the extra fans.

See link for venting tips: https://www.fridge-and-solar.net/fridge_vent.htm Quote from the article: Venting of a Gas/Electric Fridge is NOT about how much venting the fridge has,
but it IS all about how much correct venting the fridge has.

[field & stream]

ITSNO60: this is a VERY helpful posting and link. THANK YOU !

[drbrick]

Hi Ray nice write up basically we follow the same procedure that you have outlined in your wonderful post. Like you we run 200 w on the roof and also carry 160 w suitcase which we run through the umbilical cord on our international 25. This year we added two lithium batteries which we have found much better than the AGMs or the Trojans that we replaced. Like you we have a roof vent for our wonderful refrigerator. We also begin life by plugging it in to bring it to temperature usually takes 24 hours to reach 38 degrees Fahrenheit. One of the most important tricks that we have found is do not over pack the refrigerator it does need air circulation. we have never found any difficulty in running our refrigerator in temperatures in the mid 30° Celsius. For once I would have to say that Airstream Inc actually did a good job in installing the dometic refrigerator. I should add all we do is Boondock. Our boondocking happens to be in British Columbia Canada and the only struggle that we have is finding enough Sun in our boondocking in the wilderness of British Columbia that's because we have trees. Other than that life with our International 25 is good thanks for your wonderful post.

[uncle_bob]

Hi

Depending on the absorption fridge you have, it will pull an average of 0.6 to 1.2A on 12V once it's cool / running on propane. If you have fans, they will add to this. 0.6A is 14.4 AH a day. 1.2A is (big surprise) 28.8 AH a day. Fans could pull <0.3A, they could pull >1.2A. It all depends on which ones you have and how they are controlled.

All of this is very much in the "manageable" range for stock batteries with modest solar supplements. Yes, the 1.2A fans on a 1.2A fridge would be nutty, but that's not a combo you see outside the "extreme" DIY zone.

When trying to cool down and running on 120V, an absorption fridge pulls considerable current. If you are running off of a 15A circuit, and the converter charger is also running, don't plan on firing up the toaster oven ....

Another thing to watch out for:

You head down to the store. Like all stores, they want to sell you 96 or 128 bottles of water at a time. Of *course* you buy the ones on sale. Look at how much you save !!! . Now you get your hot water supply out to the trailer. Best not to pack it all into the. fridge. Water absorbs a *lot* of energy cooling down. Your poor ammonia pipes simply aren't going to keep up.

Same thing applies to large quantities of other beverages that need cooling. It also applies to that 120 pound fish you caught and are about to put in the freezer ....

If you are unable to plan ahead (or if you discover the breaker tripped on the feed to the trailer ....I have data on this ... ) there is no *good* way to speed up an absorption fridge and get it cold in an hour. It's not going to happen. You need a plan B.

Cooling down fast is what the compressor based "ice chest" gizmos are great at. A Dometic CFX3 will get to fridge temp in under a half hour. If you are a 2 hour drive from Costco, they are useful for that as well. ( Where were these things when we used tents !!!)

Any fridge needs to be open to air out when it's not running. It also needs to be clean from any spills. The alternative is a stinky fridge full of mould ..... yuck. Bleach and water will fix the issue if it happens.

Lots of fun !!!

Bob

[Ndcctrucks]

I might add, for the benefit of newer users who’ve not had the time to read as much as some of us:

1. Using a small D-cell-powered interior portable fridge air recirculating fan helped ours cool in empty pre-trip mode quite quickly; about 6 hours starting at 95 F.

2. Absorption refers are SENSITIVE to being LEVEL. There was no specification given in our Dometic owner’s manual, but multiple posts mentioning DAMAGE to the external cooling system inspired me to contact Dometic. In reply, I received an image which noted that this machine’s maximum out-of-levelness was 3 degrees left-to-right and 6 degrees front-to-back.

Using an inclinometer, this turned out to be nearly perfectly level tongue-to-bumper!

Try it, you’ll see.

So be careful! Some even say to turn it off in mountainous driving.

[aftermath]

6 degrees is a lot. According to my trig, if you measure from the center of my trailer, it is roughly 12.5 feet from the tongue. That would be 150 inches. The vertical height above the tongue would equal the tangent of 6 degrees times 150 inches. This comes out to about 15.5 inches. Level?

[Jeff7176]

We have a 25' trailer with the fridge chimney and it cools exceptionally well on propane... usually setes at 32 on the panel display, and our ice cream freezes solid.

[GCinSC2]

From the Dometic Refrigerator Training Manual, page 13

Manual can be found here https://myrvworks.com/manuals/ select refrigerators, Dometic and the document is Dometic Refrigerator Training.

[Ndcctrucks]

Originally Posted by aftermath

6 degrees is a lot. According to my trig, if you measure from the center of my trailer, it is roughly 12.5 feet from the tongue. That would be 150 inches. The vertical height above the tongue would equal the tangent of 6 degrees times 150 inches. This comes out to about 15.5 inches. Level?

My refrigerator faces the curb side, so front-to-rear would be road side-to-curb side. The spec is oriented to the refer, not the trailer.

3 degrees side-to-side (of the refer) would be tongue-to-bumper on my trailer. My driveway is quite sloped so getting it level front-to-rear requires the use of 26” jack stands at the front corners of the frame and only gets me to 2 degrees off-level.

GCinSC2::
THANKS!! I have that but couldn’t paste it into my text thru my phone.

[SuperTrouper]

This is great information! One thing I'd like to add for the camper in a a hurry, when retrieving the trailer from storage, I take a coupla bags of ice OR two frozen 1 liter bottles of water from our deep freeze with me. When I prepare the trailer for travel, I plop the ICE / frozen bottles, one in the freezer section and one in the fridge section to help with cool down. Then I open the LP valves, light all the stove burners and start the furnace for a minute to purge the LP lines of air and THEN start the fridge on LP. This helps get the fridge to operating temp quickly (coupla hours) - Brad

[aftermath]

Ndcctrucks, I think you and I agree. The bottom line here is that you should have your fridge level when running. It does not have to be “PERFECTLY” level as the Thumbnail provided by GCinSC2 has shown. I read once that your trailer should be level enough to where you feel comfortable in it. I am a bit more persnickety about feeling level so I take some extra steps when I set up.
I also found the comment, “This is refrigerator leveling, not the vehicle” confusing. Uh, what? Since my fridge is attached to the floor of my trailer, when the trailer is level, so is the fridge. An allowable 3 degree error would result in about 7 inches off level out at the ball on my 25. An inch or two maybe, but 7? What would it take to actually damage one of these things?

[ITSNO60]

The nice thing about the Fridge Defend id I don't have to worry when parking somewhere (not camping) and can't get level, the Fridge Defend will shut it down if there's a problem. I still try to get level but sometimes it's impossible at a trail head or a restaurant

[thewarden]

Another trick we have learned. We always travel with bottled water. I know, not environmentally friendly but... The day before we a scheduled to load the fridge, I put about a dozen bottles in the home freezer and freeze them solid.

As most others do, I also run the fridge for a couple of days before we load. When we load the fridge I distribute the frozen water bottles throughout the fridge and they help keep the fridge temps down. As they thaw, they make for a nice cold drink on hot days and I replace them with frozen ones that I put in the freezer earlier. And so the cycle continues.

Several frozen bottles of water in the fridge really help the fridge recover when opening and closing the fridge door. And we always have nice cold water to drink and all the empties go to a bottle depot in the area we happen to be at for refund and recycling.

[ITSNO60]

Originally Posted by thewarden

Another trick we have learned. We always travel with bottled water. I know, not environmentally friendly but...

We do the same but made a change to how we do it. I drink a lot of bottled iced tea, the square Pure Leaf bottles. So we save the bottles and refill with water from our filter at the sink and keep them in the garage fridge, then pack them along as you do. I also keep 2 gallons of drinking water under the sink in re-fillable bottles, then just refill the iced tea bottles when empty. The iced tea bottles are tough and have a wide mouth, and they are square and fit places very well. We used the same ones all summer and they are refilled and back in the garage fridge. No more plastic in the trash and no more cheap plastic bottles that pop in the cup holder making you think a rock hit the windshield.

Next I think we will start making our own tea and stop buying and throwing away so many bottles, just refill the ones we have.

[Fungus]

Great thread.

Propane mode won’t work well with a dirty orifice. Soak it overnight in alcohol or Brakleen. Let it dry. Reinstall. The flame should roar. If it’s blue but doesn’t roar it isn’t enough flame. I was on the verge of replacing the fridge because no cold on propane. Cleaned the orifice. 78 degrees to 18 and 43 in three hours.

If still not freezing check propane pressure with a manometer. Easy to make one at home: six feet of clear half-inch tubing, a two or three foot long 2 by, a few zip ties, ruler, and pencil. Sone folks use dye. Don’t. Should be 11” of water while the cooktop is running. I tested mine at the outside low pressure outlet. If not 11”, adjust or replace regulator at the tanks.

[Ndcctrucks]

aftermath:

Sorry I was in a hurry, at work.

“…refer leveling, not trailer…”

To be clear, I was pointing out that the Dometic requirements for leveling are in reference to the refrigerator’s front and sides, not the trailer’s front and sides. A refer mounted with the door facing to the front or to the rear of the trailer would allow 6 degrees of tilt, which is a LOT.

But since most refers are mounted with the door facing to the curb side or the road side, there is less tolerance for out-of-level. I felt this is a detail some might miss, but could ruin their refers if they mis-interpreted the instructions; so I felt it best to point out that the refer’s orientation within the trailer comes into play when measuring level.

Feel like we hijacked the thread; apologies to all!

Lastly, there are a few videos available on a popular video site in which people explain how having an absorption refer unlevel can cause an internal chemical reaction resulting in the fluid within to crystallize resulting in blockage and failure.

MANY GREAT suggestions here!!

This thread should be a sticky??