Dometic Refrigerator Issue...

[danrlewis73]

I have a 2006 Rockwood Rhino HW256G that I just returned from our first trip with. My issue is that the fridge only operates on AC or propane. The DC circuit seems to not operate as it's supposed to. The battery is charged. The tow vehicle connection is good. I've checked all of the fuses and they're all OK, too. I plan on contacting Dometic when I get a chance. Any ideas?

[fonzie]

Provide make and model # of your fridge......

[pgandw]

Originally Posted by danrlewis73

I have a 2006 Rockwood Rhino HW256G that I just returned from our first trip with. My issue is that the fridge only operates on AC or propane. The DC circuit seems to not operate as it's supposed to. The battery is charged. The tow vehicle connection is good. I've checked all of the fuses and they're all OK, too. I plan on contacting Dometic when I get a chance. Any ideas?

The newer high wall PUPs often have larger fridges that do not have a DC mode. They are also thermostatically controlled by a DC-powered control and ignition circuit board. While driving you either run the fridge on propane or leave it off, like the travel trailers do. Researching the fridge would confirm or refute my theory.

Fred W

[f5moab]

If it does come with the three way fridge, which would be noticeable since there would be the propane controls and two switch; one red (DC) one green (AC) the DC sucks. I have traveled 5 hours with DC plugged in and the fridge is barely cold. I have plugged it in the night before to AC, then traveled five hours and it is nice and cold.
My opinion is the DC is good to keep it cool, but really sucks at getting it cool.
As for propane, on high it can freeze every thing in the fridge is hours.

[Still Kickin]

Originally Posted by danrlewis73

I have a 2006 Rockwood Rhino HW256G that I just returned from our first trip with. My issue is that the fridge only operates on AC or propane. The DC circuit seems to not operate as it's supposed to. The battery is charged. The tow vehicle connection is good. I've checked all of the fuses and they're all OK, too. I plan on contacting Dometic when I get a chance. Any ideas?

So, to recap your dometic fridge is duel fuel(AC110v/propane). Since it uses absorption to cool, your heat source is either an electric heating element or a propane fired source to provide the necessary heat for cooling. Not sure what your question is regarding DC. That power source would drive your fridge s' electronics/controls, it cannot provide the necessary current needed to supply heat , which in effect drives the cooling cycle. Hope that helps.

[f5moab]

Looking at the specs for used ones; they all appear to use a three-way fridge!

[vinmaker]

I also owned that model and I recall it being a 3 way fridge. As was said, it really will not cool down too well on DC only. I found DC to be pretty worthless. I feel they only properly run on AC or propane. That being said, I would not nuts and spend all kinds of money on getting it fixed if the DC mode is in fact not working.

Vin.

[pgandw]

My experience with 3 way fridges is that the DC mode can at best maintain the fridge temp while towing. I pre-cool the fridge before leaving on a trip for at least one night on AC at max cool.

I switch to DC mode after the tow vehicle is hooked up to avoid running down my batteries. When I arrive at the site, I turn off the fridge even before I disconnect - again to keep my batteries at max charge. After setting up the A-frame, I connect shore power (if available) and turn the fridge on AC. If shore power is not available, I start the fridge on propane.

FWIW, the smaller PUP and A-frame 3 way fridges do not have thermostatic controls, and do not have a DC control circuit. They run continuously with AC heat input adjusted by a knob and propane flow adjusted by a valve on the gas line. DC mode is a fixed setting, and not as much heat as the other two.

About the 2nd night in camp, I have to back off the AC or propane setting some to avoid freezing the food and drinks.

The fridge cools much better when fairly full of stuff. The different temps of the food and the cooling coils promote a stronger convection air circulation than just a fridge full of air.

You can tell whether the fridge is working by feeling the insulated "chimney". On DC, the chimney will get warm, and on AC or propane, it will get hot.

just my experiences
Fred W
2014 A122 with 3 way fridge
camping our way through Colorado and adjacent states one weekend at a time
previously 2000 Coleman Westlake with 3 way fridge

[danrlewis73]

Thanks everyone for your replies. It is, in fact, a Dometic RM2354 3-way fridge unit. The AC and propane settings seem to work OK. But when I switch it over to DC it hesitates for a second and then the "check" light comes on every time. I checked the fuses on the camper power converter and they were fine. I also checked all 3 fuses in the power unit of the fridge itself. All are OK. I've used the propane setting during transport without incident. But, I'd like to use the DC mode. Only because I keep wondering if it's still lit every time I stop for whatever reason. But, if I can't get the DC to work, I'll survive.

[fonzie]

Here is manual in case you don't have. To operate on DC it needs a very good DC supply,meaning full charge battery and engine running is recommended. Also wire size feeding fridge from battery to be proper size otherwise it will not operate properly due to voltage loss....