Dometic NDR 1292 Not Cooling

[hanknjoycew]

I have display lights and unit works on both gas and electric. Cooling unit is not blown (I have had 2 blow out and know the symptoms). I did accidently run the batteries down to at least 11.4 yesterday while having service. I am running generator now for batteries and have frig on gas (was told gas works faster..?). I will check freezer in a couple hours for signs of cooling.

I have one of those ARP units which is on and seems OK. I checked the only frig fuse I could reach and it is OK. The MH is on a slight incline (2-3 degrees) in driveway, but that has not been a problem before.

Would low voltage cause the cooling unit to go off line? Should I expect to see some signs of cooling in freezer in a couple hours?

Supposed to travel today and need frig to keep insulin and other essential stuff.

Any thoughts appreciated.

Hank Whitney
SKP 67414
At Home in Custer SD
443-799-0045

[Kirk W]

5 minutes ago, hanknjoycew said:

I have one of those ARP units which is on and seems OK.

I'm not quite sure what this means as I too use the ARP. If it was flashing a code that means it did see some problem. If it senses a high temperature it will shut off for a time and as long as the boiler returns to normal temperature, it turns the refrigerator back on and no error is displayed but you can read the history if you use the ARP instructions. 

8 minutes ago, hanknjoycew said:

Would low voltage cause the cooling unit to go off line? Should I expect to see some signs of cooling in freezer in a couple hours?

It should operate fine down to a point below 11V and usually somewhere near 10.5V. But if you checked voltage after the 12V was all off for a time, batteries do recover somewhat after resting so the voltage would have been lower when under load.  I would not expect to see much temperature change in only 2 hours but you should be able to see improvement in 4 hours and back to normal in 8 or less. 

 

[kinseypw]

We have had this happen a couple of times in 3 years with our Dometic unit. I switched the frig off and let it some to room temp, then reconnected and turned on propane. I monitored cooling by putting a meat thermometer probe against the cooling fins. On our unit it gets down to 32 overnight but you can see some drop in temp fairly quickly - 10-15 mins

[hanknjoycew]

Turns out I had a senior moment and parked the MH in our gently sloped driveway "after" I had let the battery voltage drop rather low. After 24 hours (and an awkward visit by my mobile RV tech Jim) the unit started cooling again. Although I had parked this way before when getting ready for a trip, Jim said the age of the cooling unit contributed to a likely temp blockage which eventually freed up. Lesson learned - even with "newer" RV absorption frig's, keep 'em level.

Hank
SKP67414
2005 Mandalay DP
In Lusk WY On the Road to Arizona

[Ray,IN]

 Both Dometic and Norcold state in installation instructions  3 degrees side to side, 6 degrees front to back, as viewed looking at the refrigerator front; is maximum safe operation limits.

The ARP unit should detect a boiler tube over-temperature  condition and turn off/on  to stay below the over-temperature setting. Without the ARP the boiler tube can over-heat to the point it weakens the metal tubing, while also causing a chemical change in the absorption mixture which slowly allows the solids to block the cooling system.