Dometic New Dimensions Refer #NDR1292

[R_nilsen@msn.com]

We have a Dometic New Dimensions refrigerator model NDR 1292 in our 2001 Tradewinds Motorhome. For the last couple of weeks the temp on the inside of the refrigerator has been dropping. I checked a couple of troubleshooting websites and thought I would check the electric side first as the refrigerator worked fine on gas. The recommended ohm reading on the electric heaters was in range. The 12Volt fuse was fine. Now the refrigerator is barely keeping temps of 41 deg. on gas. The seals on the door are in pretty good shape. Has anyone had simular problems and found a reasonable cure?...

[wolfe10]

Bob,

You say: "... the temperature on the inside of the refrigerator has been dropping"

And then: Now the refrigerator is barely keeping temps of 41 deg. on gas".

Is it a problem with the refrigerator being too cold or hot?

Has it been defrosted lately (i.e. less than 1/8" of ice on the freezer plates?

Have you checked the door gaskets (dollar bill test)?

What is the outside temperature? That side of the coach facing the sun?

Brett

[R_nilsen@msn.com]

Correction...( the temp on the inside of the Refrigerator has been rising not dropping). Also, it has been very hot here (mid- to high 90s) and the Refrigerator is on the sunny side of the coach. Not sure what the dollar bill test is but when I close the door on one there is some tension when pulling one out. The Refrigerator is defrosted and there's very little ice on the fins. After a full night of the door being closed the inside temp made it down to 39 last night on the highest setting in gas mode. It won't go below 45 on the electric mode. Thanks, Brett, for your imput.

[wolfe10]

Yes, the "Dollar Bill" test is to insert a dollar ($10 bills work better and $100 bills almost insure success) all around the refrigerator gasket. Close the door on the bill and insure that you have the same amount of drag all the way around. This suggests that the door is centered in the opening and that the gasket is sealing well.

Also, check the condensate drain hose (outside access door) to make sure the restriction is in the end of the hose. If not, hot humid air rises in the tube and enters the refrigerator.

Is the refrigerator in a slide (therefore side upper/exhaust vent) or solid part of the coach (therefore roof-top exhaust vent). Clearly, the roof vent is more effective at venting the heat produced by the cooling process?

In either case, you can gain some efficiency by installing two 12 VDC muffin fans at the top of the cooling unit exhausting UP. They can be controlled by a switch that you manually turn on or by a thermostat.

There is also some fine tuning that you can do if your coach builder did not do the most efficient installation. Read your refrigerator owners manual for recommended clearances-- particularly clearance to back (outside wall). If back clearance is excessive, consider using foil covered foam insulation board on the outer wall which will both bring clearance dimension into specs, but will also provide some insulation from direct sun. Also the shape of the top of the cabinet if a slide mounted unit. I have seen installations where there was a "heat trap" at the top with the wall mounted upper vent BELOW the level of the area where the heat collects.

Obviously, the other variable that you control is the number of times the refrigerator is opened, particularly in the hot part of the day.

Brett

[jbell]

Also check the position of the thermostat on the cooling fins. The thermostat will slide up and down on the cooling fins and if everything else is working properly try sliding the thermostat up the fin to increase cooling (make it colder).

[R_nilsen@msn.com]

Thanks, Brett & Jimmy for the info.

The door seal seems to be working properly. I noticed the drip tube had no restrictor in it so I installed a rock that still lets droplets by. I moved the thermistat on the cooling fins up also. Waiting to see if that helps, also will look at installing a fan tomorrow if there's still a problem. I'm hoping I can remove the roof vent cap and put the fan in there somehow and routing the 12 volt wiring down and back behind the refer rather than sliding the refer out to put one near the upper back. thanks again for your help...

[wolfe10]

Yes, you should be able to access the top of the cooling unit from the roof by removing the cover. Then just drop down the + and - wires. I routed my fan + to the panel controlling interior 12 VDC lights next to the refrigerator-- just replaced a two gang switch with a three. The amp draw of the fans should not be an issue.

DO insure that they exhaust UP. Turn them on any time the refrigerator is under a real extra heat load-- that side in the sun, just turned it on or defrosted, etc.

Also while that roof cover is off, check clearance dimensions to the outer wall. If excessive, should not be that big a job to use builder adhesive to attach strips of foil covered insulation cut to fit through the roof vent.

Brett

[R_nilsen@msn.com]

Well the weather has cooled here now about 20 deg cooler than last week and moving the thermostat up on the cooling fins, restricting the drain, seems to have improved the efficiency of the refrigerator both on gas and electric. The refer inside temp is dropping to 34 deg at night both on gas or electric. I'm still going to install the muffin fans as soon as I can find a good source for them. The temps are going back up to near 100 later this week.

thanks Brett and Jimmy for your help... We priced a replacement (about $3500) so we'll just keep on tweaking this one for as long as we can.

bob

[wolfe10]

Bob,

Don't know what area of the country you are in, but, any computer store should have 12 VDC muffin fans, or look on the Internet.

[Smosher]

I had a neighbor that his manual said that it would not work in high altitude. His started beeping when he had to park without shorepower. His started to beep and he couldn't keep it lit, the LPgas part. When hooked up to power it worked great.

Steve Mosher

[pmtelt]

Mine has stopped cooling all together. It's in a 2000 Rexhall RoseAir diesel pusher. I have moved the thermostat and that didn't help.

It's getting fuel, the burner is burning and it still not cooling. When connected to shore power it won't cool either. The lights above the unit are on but (No body home) It won't cool either.

Anyone have any suggestions?

H E L P!

BTW, We are in middle TN at 25 foot elevation.

[BillAdams]

My advice......good time to throw it out and get a residential fridge!

[wildebill308]

Bob, one thing I have done is to take a small 110 fan and position it so it will blow up over the coils. I like the muffin fans but if you have a small fan I would try it till you can get some muffin fans. Here is one source for them.

https://www.amazon.com/s/?ie=UTF8&keywords=12+volt+muffin+fan&tag=googhydr-20&index=aps&hvadid=153656257573&hvpos=1t1&hvnetw=g&hvrand=3371679124492349892&hvpone=&hvptwo=&hvqmt=b&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9027284&hvtargid=kwd-734702259&ref=pd_sl_5tgrxqc18a_b

pmtelt, Is your refrigerator a Dometic? It does sound like a bad cooling unit. 

As  Bill A said a residental might be something to look at.

Bill

[manholt]

Dometic was a fine product in the 70's and 80's !  It was a Swedish Co., Then a Belgian Co. bought it and it started going downhill from there...NorCold tried with out much success to fill the void...now, most folks go to a residential make,  Mostly Samsung, they don't have to have a pure Sine wave Inverter/Converter.

[jleamont]

We had a Dometic Americana in the last coach. It was original, 1998 worked flawlessly for the 7-8 years we had it. Thetford/Norcold should stick to toilets, they manage waste well .