Refer fins---frosting up a lot

Hi everyone,
We are currently workcamping in Prosser, WA--high desert. For awhile we had a problem with the refer gaining temps throughout the day---I installed a small solar fan next to the coils and it worked great along with lowering the temp setting one notch. NOW we have major buildup of frost on the fins---what is the best method to remove??---why did we get it?? Should I adjust the small slide on the fins?
I checked the outlet hose and it appears no water is coming out, but does not seem to be blocked, unless there is some ice in there too??
thanks
al

I just open the door and put a table fan directly on the fins, takes less that 5 min the ice falls off into the tray. I remove it and resume life. You don't want to use a heated source like a hair dryer, just plain air. My refer need this treatment about every three weeks. I have never really seen a change by moving the thermister to a different position. I did put some pipe insulation on mine to "fool it" into calling for more cooling, seems to have help by about 5 degrees.

Ours have a little bit of ice on them, but the refer seems to be cooling just fine. Here, it's probably from the spate of high heat and humidity and me going in/out of it for cold ones.

Our's has had frosty fins for as long as we've owned the rig. I have tried everything known to Dometic and a few service technicians to prevent it. We finally gave in. Our resolution is to turn off the reefer for a few hours once a week. This takes care of the fins. We still have to defrost the freezer about once a month.
As a side note, the more frost builds, the reefer temps go up. We generally see our reefer temperature in the mid 30's. When it gets up to just over 40, we turn it off to defrost the fins.

A circulation fan inside the refer helps tremendously. Under most circumstances, we drop the setting down 2 notches, other wise we wind up with the water slushing in the fridge.

Have ya checked to be sure the defrost switch is on? (upper right corner of the door frame).

MC9 said:

Have ya checked to be sure the defrost switch is on? (upper right corner of the door frame).

Click to expand...

The "Defrost" switch only turns on a heating element in the door frame to warm the seal and prevent condensation on the frame and seal.

There is no defrost sequence on the refrigeration unit. I agree that a small 12VDC fan inside helps by evaporating the ice, and when it builds up enough, I use a hair dryer with the heat on low and the fan on high. It gets the ice melted quickly without warming everything in the fridge.

We have a Dometic Refer. We get a few ice sickles on the fins in the Refer once in a while but not much. We never get frost on our fins. In the freezer it gets frosted but we only have to defrost maybe twice a year. Just did it this week. Ours is built inside the trailer not in a slide.

I have seen others that had SOB's and had to remove a lot of frost off of the fins an defrost the freezer every month. Don't know what the difference is to cause this.

BC

Thanks everyone,
We did take your advice and used a hair dryer with no heat and the whole process was complete in about a half hour. I ask, on another thread, about the slide on the fins and people said that moving it higher would be colder, so going to try that too. Somewhat confused why we have a temp setting 1 to 5 and also the small slide on the fins?? I also installed a small solar fan in the back near the vents.
al

I've looked through the operation manual several times and still can't find any reference to that slider device. even in the replacement parts list.

I think sliding the thermister up and down to change temperature is an urban RV myth. If you think about it, it would be like having two temperature controls and one might ask, why. If you want colder temps, try insulating it with pipe insulation or drill out a piece of styrofoam to insulate it and fool it into calling for more cooling. I did this with other mods posted elsewhere. With all the mods, I achieved temps of 28 degrees when the coolest prior to that had been 40 - 42. I was sick of meager temperatures of 40 and up to 50 in the heat of the day, so I did all the mods at the same time, baffle at top vent, sheet metal tray at top of refer with sprayed in foam insulation, wiring of the dual stock fans to a toggle switch so that I can leave it on if desired and insulating the thermister. I am happy as can be with the results, but just don't know which mods did the most. I have learned that most slide refridgerator are poorly installed with inadequate insulation resulting in hot air pockets at the top and sides and poorly designed top vents that do not force the cooling air over the cooling fins before it can escape, hence the baffle. These absorbtion refers were designed for roof vents and unless the manufacturers do a better job with the installation, we will continue to have poorly performing refrigerators in kitchen slides.

It can make a slight difference because the temperature is not uniform throughout the compartment. Locating the thermistor as high as possible (it's warmer at the top) could cause the refer to call for more cooling. Personally, I've never had it make more than about 2 degrees difference between all the way at the top of the fins, with the thermistor almost touching the top of the compartment, and it completely removed fromt the fins, laying in the drip tray.

Wow,
we have a 2008 3670RL and have not encountered this problem as of yet. The most we have used the frig. is three weeks straight. We just retired and I am sure we will do a lot more travel. But for now just getting property ready so we can leave it. all your info is good to know incase we have same problem. we are also thinking of putting a small fridge in basement for the cold ones as not to keep opening the fridge in RV. Anyone done this yet. Does it work OK?

Here are 3 links that explain RV refrigerators fairly good. I like the first one the best. Also the outside controls 1-4 control the levels of cold from high to low (1 is the warmest 4 (or 5) is the coolest). The thermistor will control only the refrigerator part and not the freezer part. For example: If your outside the box is set on 3 and you refrigerator inside is 39 and freezer is 30 you move the thermistor and it may change the refrigerator to 35 but the freezer will still be 30. If you put the outside control on 4 the freezer temp might be 25 with the refrigerator at 37. So you see the thermistor only control the refrigerator part of the box. Remember although we call it a refrigerator (or frig my DW still calls it an icebox) it is actually a refrigerator/freezer. A two-part unit. One side refrigerator and one the freezer. How this clears it up some. BTW there are tons of great RV repair and maintainance videos on You Tube from a variety of sources.

http://www.youtube.com/watch?v=Ll-5uZqIxdc&feature=related

http://www.youtube.com/watch?v=UwJ8Mmu_oLY

http://www.youtube.com/watch?v=fiODEcUAkeU&feature=related

At the very least, even if your not having trouble, take a look at the insulation at the top and sides. I bought two rolls of 1 inch insulation and rolled pieces up to form 2 inch thick rolls and forced these into the top and side spaces. Mine was very poorly insulated. I spend almost two years just tolerating the refers poor performance until the hot summer hit this year while we were traveling in Colorado 97 degrees some days. My refer was getting up to 54 on some days and food was starting to spoil.


After all the mods my refer started to get too cold after the first few days and I had to turn it down to setting 4. It was getting down to 25 - 26. A temperature that I never dreamed of achieving.