Running refrigerator on propane

RoadHog

2021 Unity MB
We will be camping w/o hookups for the first time soon, and am making sure everything works as expected. When I set the refrigerator to run on propane, it tries to ignite (beeps for 20 seconds), but fails. Propane switch outside is on, stove ignites, furnace works. Tried numerous times. What could I be missing?
 

JoePhoenix

2016 Unity TB
To make sure you're getting LP into the coach, does your stove work and stay on?

Also, from the manual I posted yesterday:

4.3.2 Gas operation (Liquid gas)

The refrigerator must be operated using liquid gas (propane, butane) (no natural gas
or town gas). When using LPG gas, please consider that the burner needs cleaning at
shorter intervals due to the gas combustion method (2 - 3 times per year recommended)

For physical reasons, gas ignition faults could occur starting from an altitude above
sea level of approx. 3280 ft. / 1000 m (No malfunction!)

On the initial refrigerator start-up or after a cylinder change, air may be trapped in the
gas line. To purge the air from the lines, switch on the refrigerator and any other gas
appliances (e.g. stove) for a short time. The gas ignites without delay.
 
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RoadHog

2021 Unity MB
Thanks - Have run the stove for 15 min or so, and furnace for 5. Fridge runs fine on 120/12 volt. I'll get the better half to switch it to gas while I am outside near the vent listening for gas/ignition attempts.
 

smiller

2008 View J (2007 NCV3 3500)
It can take several tries, sometime more than you might expect if there is a lot of line between the tank and refrigerator, to get the burner to light initially. Keep trying, you just might need to purge more air from the line.
 

J&B

2015.5 UnityMB U-Lounge
Try unplugging the shore power and it should automatically revert to propane.
 

J&B

2015.5 UnityMB U-Lounge
Make sure the switch is set to auto.
 

Ann Ossinger

2016 Unity MB EuroSport
Thanks - Have run the stove for 15 min or so, and furnace for 5. Fridge runs fine on 120/12 volt. I'll get the better half to switch it to gas while I am outside near the vent listening for gas/ignition attempts.
Sounds like exactly the process we go over on our old (17 years) travel trailer! Some things never change, even when they cost $100k more!!
 

icarus

Well-known member
I beleive most 3 way fridges need a 12 vdc source for the control board and the ignitor and the gas valve. Confirm that detail, and then confirm if you have 12 vdc. Then check to see if the ignitor sparks and the gas valve opens.

Lp fridges are ridiculous simple, but drought with issues if you don't know how to deal with them. Cleaning the ignitor and blowing the flue and burner clean is an essential routine service. rust from the boiler can (and does...often) fall onto the burner making it either impossible to light, or not able to sustain a proper flame. Canned air, or compressed air is your best friend to blow out burners and boiler chimneys.

Icarus
 

RoadHog

2021 Unity MB
Thanks to all - problem was user error (of course). The Dometic manual we have is not for the RMD8555 (they don't have the manual for it on their web site), and the illustrations in the manual we have don't match the fridge. Turns out there is an alert/alarm warning light at the far right end of the control panel, after the temperature setting LEDs and away from all other buttons. Apparently, after the first attempt to use gas, the alarm light went on (because it didn't ignite) and I didn't notice. When I went out to listen at the vent while my wife tried to set it to gas, she saw the alarm. It's also a button, and pressing it resets the alarm. After that, selecting gas worked perfectly. Doh!
 

RoadHog

2021 Unity MB
Joe - While that is the correct model number, I think it applies to a European version (talks about 230VAC, not 120). In addition, the images don't match the fridge. I has previously contacted Dometic USA, and they sent a manual for the RML8555. It also doesn't match. I talked with customer support; apparently, the North American version of the RMD8555 is too new, and they haven't produced an updated manual yet.
 

JoePhoenix

2016 Unity TB
Yeah, RoadHog. I read further and that's why I deleted it.

This is not acceptable. They're delivering product to us, but they're not providing the correct documentation. Apparently Dometic either doesn't have tech writers or they don't own a scanner. Either way, it sucks!

Joe
 
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MWSHAWJR

New member
I have an RDM8555 and the blue LED light on left end next to the red blinks and beeps alarm, but both refrig and freezer working fine. As stated earlierI have no manual so I called Dometic for quick solution or how to reset. They said they could not diagnose or give a solution but that I should take it to a dealer for repair.Since I am on a cross country trip to attend a wedding and only 1900 miles on my new coach. I really don't want to search out a dealer and half a day or more solving a simple reset problem. Appreciate any advice. M. Shaw
 

MWSHAWJR

New member
Just walked by frig after my long complaint thread and light is not blinking and no alarm. Maybe the RDM8555 doesn't require a manual as it apparently heals itself!
 

RoadHog

2021 Unity MB
MWSHAWJR - After my issue with the propane was solved, we were camping w/o hookups without further issue. That is, until shortly after midnight on the first night on propane. Refrigerator starts beeping, and blue LED starts flashing. Of course, the manual we do have (the European version) was worthless. Turned it off and back on, switched to 12VDC, no change. The beeps repeated every 2 minutes - hard to sleep that way. Ended up turning it off until morning. Turned back on in the AM, still blinks and beeps. Turned on genset to try 120VAC; no difference. Ended up switching back to gas and tolerated the beeps during breakfast. Noticed (as you noted) it still cooled. We were sightseeing that day, and noticed after we were on the road 5 minutes or so, no more beeping. Called Dometic USA later that day, got the same response you did (take it in for service). It's worked fine since.

After the fact, I remembered when we were preparing to leave and loading the fridge, the door was open for a bit, and it did the same thing. I suspect that is the door ajar alarm, except the doors were firmly closed when it went off in the night. Maybe something is faulty in the switch. Whatever it is, it's going to be hard to get someone to diagnose a transient problem like this.
 

jackfish

Active member
My Dometic RML8555 is dead. It is not adequate for full timing. I will be replacing it with a Nova Kool RFU6800 12 volt DC compressor fridge in May.
 

Bone Head

2014 LTV Unity MB
Jay, keep us informed of how this replacement goes for you. I suspect that a lot of us will be looking at doing something similar.
Bob
 

jackfish

Active member
The Nova Kool RFU6800 is installed. 35 degree fridge, 20 degree freezer, 5 amp draw at 12 volts cycling about 50 percent of the time with an 80 degree outside temp. Pics to follow.
 

pokiejoe

New member
Roadhog, I am a bit confused on the model you are referring to. Is it the RML8555 or is it the RDM8555. I can find a manual for the RML8555 but am not sure if the RDM replaces the RML anyway here is a link to the RML manual.

http://www.dometic.com/USA/Support/RV-Manuals/

ok I found a reference to the RDM8555 on a UK site but nooooo manuals....
 
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Peter Tourin

2020 Unity RL, ex 2012 Unity MB
I think it's RML8555 (single door) and RMD8555 (double door). When our single door fridge failed I tried to buy a double door, but they were only available in Canada, not in the US.
 

jackfish

Active member
Moved the temperature sensors today to get a better idea of what is going on. Fridge sensor is now in the door, halfway between top and bottom, and the freezer sensor is on the side, near the door, about halfway from top to bottom. 37 degree fridge and 14 degree freezer.
 

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