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Topic: 2004 MB fridge not performing well on propane while driving  (Read 648 times) previous topic - next topic
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Re: 2004 MB fridge not performing well on propane while driving
Reply #25 –
Does your 2004’ refrigerator have the big sheet metal shield in front of the burner? It was a recall item on Dometic refrigerators in RVs of your vintage, newer refrigerators came with the shield Factory installed.
If it is missingor was never installed, this coud be the reasonwhy it doesn’t run on propane while driving.
Does ypur refrigerator look like this...
https://external-content.duckduckgo.com/iu/?u=https%3A%2F%2Ftse3.mm.bing.net%2Fth%3Fid%3DOIP.DnwNmm8iafRqHmnNMwNDkQHaFj%26pid%3DApi&f=1
Or this?
https://external-content.duckduckgo.com/iu/?u=https%3A%2F%2Ftse1.mm.bing.net%2Fth%3Fid%3DOIP.2hK5uXYlMqwv4nMjSyX1hQHaFK%26pid%3DApi&f=1

The shield surrounds the burner and can help prevent the flame from being blown out when at speed.
Your 2004 didn’t come with the shield but should have been done years ago during Dometic’s recall.

Some Dometic roof vent covers are directional and cn be installed backwards.

Larry
Larry
2003 23.5' Front Lounge, since new.  Previously 1983 22' Front Lounge.
Tow vehicles  2020 Jeep Wrangler Rubicon, 2001 Jeep Cherokee
Photo Collection: Lazy Daze
Re: 2004 MB fridge not performing well on propane while driving
Reply #26 –
Good catch Larry. I never got that recall.   In addition, I just remembered that in many older refrigerators, the burner filled up with rust particles below where the flame was and the gas and air didn't mix correctly. Consequently the flame was a little above the burner screen, instead of in it like it should be. This caused an easily blown out or disturbed flame. While it looked normal initially it was not what it should be. In addition my orifice had an accumulation of 'goo'.  I removed the orifice and cleaned it with acetone, and an air compressor. After also blowing out the screen area to remove rust particles, (Thanks Ruben) the refrigerator cooled much better.  RonB
RonB (Bostick) living in San Diego
Original owner of "Bluebelle" a '99 TKB
Re: 2004 MB fridge not performing well on propane while driving
Reply #27 –
Quote from: Larry W  - 
Does your 2004’ refrigerator have the big sheet metal shield in front of the burner? It was a recall item on Dometic refrigerators in RVs of your vintage, newer refrigerators came with the shield Factory installed.
If it is missingor was never installed, this coud be the reasonwhy it doesn’t run on propane while driving.
Does ypur refrigerator look like this...
https://external-content.duckduckgo.com/iu/?u=https%3A%2F%2Ftse3.mm.bing.net%2Fth%3Fid%3DOIP.DnwNmm8iafRqHmnNMwNDkQHaFj%26pid%3DApi&f=1
Or this?
https://external-content.duckduckgo.com/iu/?u=https%3A%2F%2Ftse1.mm.bing.net%2Fth%3Fid%3DOIP.2hK5uXYlMqwv4nMjSyX1hQHaFK%26pid%3DApi&f=1

The shield surrounds the burner and can help prevent the flame from being blown out when at speed.
Your 2004 didn’t come with the shield but should have been done years ago during Dometic’s recall.

Some Dometic roof vent covers are directional and cn be installed backwards.

Larry
Hi Larry, thanks for the info, our fridge does have the shield installed so it was done in the recall before our purchase. The blue propane flame was somewhat still unstable at highway speed seeing through the video camera compare to when LD is not moving. Today I bought the same inverter Steve has been using and will wire it up soon as a dedicated power source for the fridge while driving. I pretty much give up on the propane heater when we travel. The flame just does not transfer enough heat at highway speed. The room vent appeared to be in the right position
2004 Mid Bath,
2007 Jeep Liberty Towed
Re: 2004 MB fridge not performing well on propane while driving
Reply #28 –
Another possibility is, as Ron mentioned, is a dirty jet in the solenoid valve.
All jets, after so many hours of operation, will eventually get dirty, propane contains minute amounts of oil. A layer of evaporated oil slowly builds up in the jet's interal diameter. A smaller jet diameter may not flow enough gas and/or produce enough heat to substain the flame or operate the boiler, especially in a windy environment.

Removed the shield and either unscrew or bend back the sheet metal tab that covers the jet.
Find a small wrench that fits the jet and removed it, soak in solvent and then clean with an old, nylon toothbrush.
Never push anything made of metal through the jet, it can be easily damaged.
Dry and reinstall.
Check your owners manual on cleaning the boiler’s chimney.

Larry
Larry
2003 23.5' Front Lounge, since new.  Previously 1983 22' Front Lounge.
Tow vehicles  2020 Jeep Wrangler Rubicon, 2001 Jeep Cherokee
Photo Collection: Lazy Daze
 
Re: 2004 MB fridge not performing well on propane while driving
Reply #29 –
Quote from: Larry W  - 
Another possibility is, as Ron mentioned, is a dirty jet in the solenoid valve.
All jets, after so many hours of operation, will eventually get dirty, propane contains minute amounts of oil. A layer of evaporated oil slowly builds up in the jet's interal diameter. A smaller jet diameter may not flow enough gas and/or produce enough heat to substain the flame or operate the boiler, especially in a windy environment.

Removed the shield and either unscrew or bend back the sheet metal tab that covers the jet.
Find a small wrench that fits the jet and removed it, soak in solvent and then clean with an old, nylon toothbrush.
Never push anything made of metal through the jet, it can be easily damaged.
Dry and reinstall.
Check your owners manual on cleaning the boiler’s chimney.

Larry

Thank you Larry for the reminder of cleaning the jet, I did a couple of years ago and the flame looks stable and strong when the LD is parked. I also cleaned the chimney in 2015 and rechecked it yesterday with a flashlight. Appeared clean and no carbon deposit. Given the fact the fridge works really well in both electric and propane modes when stationary, I really think the propane boiler just does not heat up the ammonia solution at highway speed.

I bought the same model inverter Steve has been using since 2017 and wired up this morning as a dedicated inverter for the fridge, a short drive test shows it work well. Thanks to everyone and particularly to Steve. The real test will be when we drive through Cincinnati at midnight to avoid traffic. Last time when we passed Atlanta at midnight, the propane boiler failed miserably, I am sure we will not repeat ;)
2004 Mid Bath,
2007 Jeep Liberty Towed
Re: 2004 MB fridge not performing well on propane while driving
Reply #30 –
Quote from: cli288  - 
I bought the same model inverter Steve has been using.....
What model is that? I've searched and can't seem to find it.

Charles

Harvest Hosts + Boondockers Welcome #23975
Escapees SKP #138195
2007 23.5' Twin King
Re: 2004 MB fridge not performing well on propane while driving
Reply #31 –
If using an inveter,, make sure to remember to turn it off when parked, it will kill the battery.
Don’t ask how I know.

One last possibility, has the propane pressure been checked recently it should have 11in/H2O pressure when it, and a least one other propane appliance, is operating. Too little pressure provides not enough heat to operate the refrigerator’s boiler.

Larry
Larry
2003 23.5' Front Lounge, since new.  Previously 1983 22' Front Lounge.
Tow vehicles  2020 Jeep Wrangler Rubicon, 2001 Jeep Cherokee
Photo Collection: Lazy Daze
Re: 2004 MB fridge not performing well on propane while driving
Reply #32 –
Quote from: Charles & Donna  - 
What model is that? I've searched and can't seem to find it.

Charles
I guess he found my original post:

Inverter for fridge...

Note that my original transfer switch in the install arced an cause the invertr to fail. I have ssince replaced it with a more robust transfer switch, similar to the model hooked on the back of the converter for generator transfer.

Steve
2004 FL
2013 Honda Fit
Re: 2004 MB fridge not performing well on propane while driving
Reply #33 –
Quote from: Steve  - 
I guess he found my original post:

Inverter for fridge...

Note that my original transfer switch in the install arced an cause the invertr to fail. I have ssince replaced it with a more robust transfer switch, similar to the model hooked on the back of the converter for generator transfer.

Steve

Thanks for your reply Steve! I am thinking of doing this also. I had already decided go the transfer switch route; have found two small 15A ones so far.

Charles
Harvest Hosts + Boondockers Welcome #23975
Escapees SKP #138195
2007 23.5' Twin King
Re: 2004 MB fridge not performing well on propane while driving
Reply #34 –
Quote from: Charles & Donna  - 
What model is that? I've searched and can't seem to find it.

Charles


Hi Charles, I found Steve's posting in 2017. The inverter is a Cen-Tech 750W simulated sine wave inverter on sale at Harbor Freight Tools for $29.97. Here is a copy and paste section. If you go to his original posting there are photos and instructions there.

Reply #2 – 4 years ago
Inverter is Harbor Freight # 69660, 750 Watts. The 12V relay is a Stinger SGP38, 80 Amp, powered thru a 50 Amp fuse from the chassis battery terminal of the battery isolator. The relay coil is switched on by the alternator terminal of the battery isolator. The wiring is 4 gauge for positive, 6 gauge for the short negative run to chassis ground. The inverter is mounted behind the cab seat on the same side as the fridge, with lots of air circulation. It does not get warm to touch.

The fridge heater draws about 350 to 360 Watts when cycled 'on', and my transfer relay is home-brew, and switches power to the socket the fridge plugs into.

Steve
2004 Mid Bath,
2007 Jeep Liberty Towed
Re: 2004 MB fridge not performing well on propane while driving
Reply #35 –
Quote from: cli288  - 
Hi Charles, I found Steve's posting in 2017. The inverter is a Cen-Tech 750W simulated sine wave inverter on sale at Harbor Freight Tools for $29.97. Here is a copy and paste section. If you go to his original posting there are photos and instructions there.
 
Thanks. It appears that model has been discontinued and is only available at some stores. At least I have a better idea of what size inverter would work.

Charles
Harvest Hosts + Boondockers Welcome #23975
Escapees SKP #138195
2007 23.5' Twin King
Re: 2004 MB fridge not performing well on propane while driving
Reply #36 –
Latest and final field report to everyone from me with a thankful mind and sincere appreciation.

After I wired the dedicated Centech 750 W inverter using alternator output as Steve described in his posting, we drove from Catersville GA back to our Michigan home, a 700 mile plus ride, we are reporting this system works very well! The fridge cycledd between 32 to 36F range including the midnight drive through Cincinnati , similar as when the LD is parked on propane or on solar power. The electric heater boiler cycled between 135F (on) to 92F (off). The engine battery voltage remained between 13.2 to 13.6V and the whole system worked flawlessly. Now we can completely ignore that damn propane boiler highway performance issue!

I believe there are still many HFT stores carry this inverter. I checked it is available in many of them along our way back from Georgia to Michigan. I bought it from the Cartersville store so I can wire it up quickly to get the fridge to work during the "snowbird return trip".

Special thanks to Steve, thanks to everyone. This is a great story showing our LD community jumps in to help a member solve a special problem. I really appreciate the help!


2004 Mid Bath,
2007 Jeep Liberty Towed