85 Dometic Fridge not constant

Discussion in 'General RVing' started by Mamajo84, Mar 28, 2007.

  1. Mamajo84

    Mamajo84 New Member

    Hello,

    I am just starting out with my first RV. An 85 fifth wheel. I seem to have a refrigerator problem and I would like to exlore any cheap tips and ideas since I cannot afford to replace the unit. The friend we bought it from swears that the fridge worked fine. We tried it several times and it would get cool and a bit of frost in the freezer, but not near cold enough to store food. Then one day right before a trip, I turned it on and freezer was -3 and Fridge was 29. I was so excited, then during out outing we could never get it very cold again. It seemed to get cooler with gas then electric. I do not hear any Loud gurgling, see or smell any leaks and the fact that it got cold enough once means that it is not crystalized, right? Is there anything inexpensive that I can try? Is there any truth to the idea of removing the unit and turning it upside down overnight? I would appreciate any helpful ideas you all might have. My aching back is tired of ice chests! ;-)
     
  2. Grandview Trailer Sa

    Grandview Trailer Sa Senior Member

    Re: 85 Dometic Fridge not constant

    Are you running it on gas or electric? If gas, you might have to clean the burner tube. It is located, from the outside vent, on the lower right under the chimney. You will have to remove just a couple of sheet metal screws to access it. Make sure you don't see a dirt dobber nest also.
     
  3. Mamajo84

    Mamajo84 New Member

    RE: 85 Dometic Fridge not constant

    I would be so very pleased it worked on either gas or electric. I have tried both with same result. Seems to get just a bit cooler with the gas, but not cool enough.
     
  4. DL Rupper

    DL Rupper Senior Member

    Re: 85 Dometic Fridge not constant

    The fridget should run at about 35 degrees or so (between33-39). What does it run at?
     
  5. Kirk

    Kirk Senior Member

    Re: 85 Dometic Fridge not constant

    First of all, it is quite normal for an absorption refrigerator to work best on propane because the electric heater is only about 60% as much heat as is the propane flame.

    The most common indications that your cooling unit is failing is to either smell an odor of ammonia in the box or the rear access panel or to see a yellow powder in the rear. Either is an indication that the cooling unit is leaking and will need replaced. Since it seems to cool fairly well, but very slowly, it is quite possible that the problem is not lost coolant. The first thing that I would do is to make sure that you have good air flow through the unit. A quick way to test to see if this may be the problem would be to set a fair size fan in the open rear access area with it blowing up into the flue area and moving a good volume of air. Once you do that, go to the roof and see if there is a nice breeze of air coming from the roof vent. If there is, that is a good sign, but if not cleaning may help and that is what I would do first. If you do have a good air flow, let it sit over night and see if the cooling rate improves. If it does, then start by cleaning the entire flue area thoroughly. I would remove the top vent, and use a good shop vacuum to remove all of the dirt, dust and rust that you can from the top. The same should be done from the bottom as well and once that is done it would be good to use compressed air to blow things and vacuum again. I suggest that you use air pressure of 50# or less to blow things out. Once that is done, look for the flue which will be a chimney type tube that comes up from the burner area and get all dirt, rust and foreign material out of the air path there as well. Do not remove the baffle from the flue, or use care to put it back into the original location if you do. Good air flow if vital to proper operation.

    Next, remove the cover from the burner area and use the same system to clean it as well. If you can spot the electric heat element, remove it and vacuum that are as well and make sure the element is clean when replacing it. After all of that is done, turn the refrigerator on to operate on propane and watch the flame as it should be a nice blue with just a tip of yellow. If it isn't the jet may need to be cleaned. It can be removed and cleaned with alcohol but use only a wood toothpick on the opening to avoid damaging it.

    When this has been done, test the unit again to see if it cools properly. If that does not do the job, it isn't good news. In addition to lost coolant, a cooling unit can become partially plugged by crystallized ammonia. If that is the problem, there has been some success in removing the refrigerator and letting it sit upside down for 24 hours to unplug it and hopefully when turned back upright the crystals will fall back into the boiler or some other low point where they will not cause a problem, at least for some time. This does require removal of the refrigerator, so it will take some serious work.

    I would not spend the money to replace the cooling unit in a refrigerator that is more than 20 years old, although you probably could get one.
     
  6. Mamajo84

    Mamajo84 New Member

    Re: 85 Dometic Fridge not constant

    Thank You Kirk for all of your suggestions. We blew out the chimney and did have some rust fall through. But I suspect that the problem was that the cover for the burner was not on. I did not recognize that the burner area was supposed to be enclosed until I read your post and tired to remove it, did some digging and found it tucked between the unit and the wall. After I closed it up, I let the frige run overnight and IT WORKED. I have a question though. How important is the flue cover? It was accidentally knocked off and we do not want to go to all the trouble of taking the frige out to replace it if not necessary. Since everything is working so well on the propane, could I just unplug the fridge from the electric socket do it does not keep trying to run on electric? Again. THANK YOU
     
  7. hertig

    hertig Senior Member

    Re: 85 Dometic Fridge not constant

    My fridge has a switch to select Gas Only, Electric Only or Automatic (Electric if available otherwise gas). You could unplug the fridge, but then you'd have to remember to plug it back in to run on electric (my preferance because it is cheaper, and harder to 'run out of').
     
  8. s.harrington

    s.harrington Senior Member

    Re: 85 Dometic Fridge not constant

    The flue cover helps conserve heat in the flue itself. So it is important though not critical.
     
  9. Giddyup

    Giddyup New Member

    RE: 85 Dometic Fridge not constant

    Get ahold of Dometic and ask about their recall' they are having right now on frigs from '97 to '02. Ask if there was a recall on earlier models.Talk to their service deparmtent. 1-800-366-3842, Patti & Bill
     

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