Two way fridge on DC?

[GMT830]

Our Dometic fridge is a two way. It works perfectly on 110 VAC, and is well insulated. We towed without power for about two hours. Everything was still nice and cold or frozen solid. But it was cloudy and 55 degrees or so. The previous owner said he spent several hundred dollars having the fridge repaired. I tried once last year to run it on propane with no luck. The selector switch does not have a solid feel at all. I would prefer to leave it alone at this point, maybe fool with it again in the fall. If it needs repair it would be easier to deal with at the end of the season.

So I'm considering running an inverter to power the fridge while traveling. Anyone done this? Any suggestions?

[Almot]

doxiemom11 wrote:
It's just like at home if the power goes out - the frig/freezer will keep things cold for a couple of days if you leave the doors closed.

Depends on the frig I guess. Whenever I had power outage - in different places and different fridges - darn thing started leaking after a couple hours. Half a day at best.

So if you freeze the meat, for example, it could still be hard, almost frozen, by the time you arrive on the camp, but I wouldn't count on it remaining frozen by the next morning.

OP - fix your gas fridge, as many suggested. DC option on a typical ammonia fridge is the easiest way to kill your batteries and inverter, as others noted.

Running propane on the road or not - up to you. All kinds of risks associated with ammonia fridge will increase when you add shaking and vibration during driving. I would rather reconsider my menu instead, choosing items that can survive few hours of warm temperature - it's not that difficult.

[doxiemom11]

We do not travel with our frig on. It stays cold for many hours. I do have thermometers and the temp changes very little if you aren't opening and closing the doors. (Norcold) If we have had it off for say 6 hours or so, I do turn it on gas and let it run for 1/2 hour or so while we stop for lunch. It's just like at home if the power goes out - the frig/freezer will keep things cold for a couple of days if you leave the doors closed.

[GMT830]

The gas is definitely working. The fins in the fridge have iced-up. Current temps are about 7 in the freezer, 35 in the fridge. I actually turned the control back a bit, don't want to freeze out the fridge. I'll check in another hour or so, then in the morning.

It won't get much of a workout tonight. Currently 47 degrees, low of 38 forecasted tonight.

[Dick_A]

Moved from General RV'ing Issues.

[CA_Traveler]

The flame is on/off. A lot of us drive with the propane on, some don't. The refer should be turned off at a gas station.

Future maintenance: Remove the top vent, remove the round spiral baffle in the flue. Cover the gas burner and Run a bottle brush (attached to a stiff wire) up and down the flue. Be sure the brush does not damage the gas burner. Vacuum and reassemble.

[tenbear]

I have always run the gas while traveling. Some others never do. There have been several threads on the subject. The refrig is designed to be used en route. I guess it depends on your faith in the manufacturers. Maybe also on your tolerance to fear???

[GMT830]

Thanks for all the suggestions and guiding questions guys. I went out this afternoon since the sun came out and looked things over.

It's a Dometic Designer Series RM2804. Separate doors for fridge and freezer. Manual selection for Gas or Electric. Separate temp knobs for either system. And it's electronic ignition, which is nice. The furnace is EI, but the stove is not, so I had no idea until I pulled the exterior cover off. Took the cover off the control panel at the bottom to get a look around. Just rods going through to the control in the back. So I flipped the switch to gas and followed the instructions. Sure enough, the light on the bottom started flashing. Push and hold the starting button, light stays out. But I can't hear anything. So I go back outside and listen. Nope, nothing. Pull the cover off the bottom of the chimney and she's burning smooth. I of course had to stick my finger in between the nozzle and tube to smother the gas. That little ignitor will wake you right up lol. And it lit right back up as quickly as I pulled my finger out. Blew the flame out, the ignitor starts clicking and it came right back to life.

Couple of questions still:
Is the flame on/off, like a typical thermostat? Or does it adjust flow rate based on demand?

I need to vacuum out the dead flies and such from the back. And there was probably a teaspoon of rust dust under the small tube in the stack. Do I need to do anything else? I've heard the vent covers on the roof can be brittle. If everything is working fine, do I leave well enough alone? Or should I try to do a visual inspection of the flue.

The vent holes in the access panel/vent are huge. There was a piece of nylon screen floating around in there. I'm thinking aluminum would be a better choice, and stay formed to the curves better.

The gas is running now, plan to leave it on all night. She is grabbing a couple thermometers at WW tonight so I can be a little more scientific than "pretty cold" or "wicked cold".

Also going to do some failure testing tomorrow. Disconnect the ignitor and see if the light flashes when she call for gas.

The big question - Can I run the gas while towing the camper?

[tenbear]

I tried this when I owned a TT. The battery got to low and the inverter quit after about 4 hours on the road. The charge line from the TV couldn't keep the TT battery charged. The inverter finally died, probably from under voltage.

[Old-Biscuit]

How far do you travel before plugging rig back in?

Fridge will stay cold for several hours provided no one is opening the door.

Which model is your Dometic?
Do you have to 'select' gas OR will it swap to gas on loss of AC power?

[CA_Traveler]

A 300W refer would use for example 300/120*11=28A. It's doubtful that the truck/trailer wiring can supply that much current. One option is to install the inverter in the truck and run a 120V cord back to the refer.

Verify that the alternator has the additional capacity.

[GMT830]

Thanks for the info guys. I'm only looking to run the fridge on DC while towing the camper. We don't intend to do any dry camping, at least not this season.

I need to pull the cover off and poke around in there to see what's going on.

[daveshan]

The resistance heater in a gas/AC frige draws a lot of wattage, the very small 5CF unit in my TC has a 150W/120v heater, the side by side in the coach is twice that. This will put a pretty big draw on your batteries, figure 13-25A and that's not allowing for inverter losses.


IMO fix the propane issue and use the inverter for watching TVs.

[Homer1]

One thing that happens to the propane side of the fridge that causes them not work, is the easiest fix in the world. Check the propane burner on the back of the fridge. It may be completely covered up with rust dust from the chimney. Just use a little low pressure compressed air and blow it out. Usually they will fire right up and work fine. I have had to do this at least once a year to every fridge I ever owned.It is cheap, easy (as always go the easy route first). If a dealer does this for you, it will cost you $50+. There is a small access door on the burner just for this reason.PLEASE DO NOT DISCONNECT ANY GAS LINES. You do not need to.

[GMT830]

I don't know that it doesn't work on gas. But I do know the selector switch feels almost broken. Just don't want to upset the apple cart at this point in the season.