Fridge Gas Jet Keeps Clogging Up

[Kingfish]

I've had to clean the gas jet and flue on my fridge (Dometic 8551) several times while on the road. It regains a robust flame after cleaning, and works as expected for only a couple of days, then I have to repeat the process.

I'm wondering if it could be related to a propane tank I picked up somewhere on a previous trip that obviously had a lot of moisture in it? I quickly disposed of it of course. All other appliances seem to work fine, but they are not fed by an orifice smaller than a pinhole.

I'm thinking maybe I should purge the gas line, but have no idea if this is even possible.

Thanks in advance for any thoughts or suggestions.

KF

[Ron in BC]

It seems to be a common situation.

Are you finding tiny bits of black carbon by the orofice? Poor photo but you can see a bit of carbon just above the orofice.

I used to think that cleaning the orifice was the reason the flame went back to full strength. But many times there wasn't any carbon bits to clean out.

At some point I began to suspect that it was the act of de-pressurizing the line that got the flame back. Maybe the solenoid was sticking or something like that. Others in the same situation have given the solenoid a couple of wacks and got the good flame back.

So maybe you did get some contamination from the tank but if you're not seeing any carbon flakes then maybe not.

You can purge the line easily enough. Make sure all propane devices are off, close tank valve, disconnect line fittings, open tank valve. Just takes a few
seconds to purge.

Ron

[Kingfish]

Thanks. I've not noticed any carbon. I'll try tapping the valve.

[Ron in BC]

Sorry, I wasn't very clear on that. They tapped the valve while the pressure was released.

Ron

[Kingfish]

Temp in the fridge rose dramatically today as we drove. When we stopped for the evening all of a sudden it started falling again back to normal. Head scratching time. When I checked the flame again tonight I found that I had failed to snap the wind guard back over the orifice/flue when I cleaned it Tuesday morning, and left it laying in the fridge cavity. Nevertheless, I depressurized and tapped the valve a few times for good measure as suggested. I'll be on the road again tomorrow so stay tuned!

[cpaharley2008]

The older Escape Dometic's were notorious for blowing out while towing. Some of us used filters and screens to help prevent the rush of air into the compartment. In addition the drain tube was thought to be a culprit. Eventually things got better, particularly in the 2nd G models.Here are some photos of my 2014 refer vent cover with screen and furnace filter material trying to prevent blow out while towing.

[MyronL]

"re: ...a common situation ...At some point I began to suspect that it was the act of de-pressurizing the line that got the flame back. Maybe the solenoid was sticking or something like that."

I don't recall seeing any signs of carbon the several times I cleaned the orifice in my 8551 and your new to me suggestion is something I will definitely try the next time my fridge goes out.

[Kingfish]

Update. After replacing the wind guard the fridge is working as it should. 95 degrees today while traveling and the fridge never got below 41.

[gbaglo]

Originally Posted by Kingfish

95 degrees today while traveling and the fridge never got below 41.

I'm guessing you meant to say above 41?

[Kingfish]

Originally Posted by Ron in BC

It seems to be a common situation.

At some point I began to suspect that it was the act of de-pressurizing the line that got the flame back. Maybe the solenoid was sticking or something like that. Others in the same situation have given the solenoid a couple of wacks and got the good flame back.

Ron

I think you are on to something Ron. After a couple of days working flawlessly on gas, it quit totally yesterday morning. Last night I removed the orifice and re-installed just to let the pressure off the solenoid. No cleaning. It was 33 degrees this morning when I got up. Outside temp was about 60.

[sunrisetrucker]

Originally Posted by Ron in BC

bits to clean out.

At some point I began to suspect that it was the act of de-pressurizing the line that got the flame back. Maybe the solenoid was sticking or something like that. Others in the same situation have given the solenoid a couple of wacks and got the good flame back.


Ron

When you talk about the solenoid do you mean the pressure regulator directly above the tanks?

[Ron in BC]

Ah, old habits die hard. I was going to nip outside and snap a photo of the solenoid for you. Reached for my camera and then remembered, I don't have a trailer outside, it's sold.

Follow the copper line up and you'll see the solenoid. It's electrically operated. Strangely enough undoing the connection to the orofice doesn't really release the pressure on the solenoid. Any pressure there bleeds out through the orofice.

To completely release gas pressure on the solenoid the pressure must be released from the "in" side that the larger copper supply line connects to. If just releasing pressure at the orofice works, great; if not releasing pressure on the inlet probably will work.

Ron

[sunrisetrucker]

Originally Posted by Ron in BC

Follow the copper line up and you'll see the solenoid. It's electrically operated.
Ron

Of course a solenoid requires electricity.
Duh where was my head at?

[KirkB]

Hi Ron,

Thanks for the tip to check the solenoid. I have intermittent poor propane cooling in my fridge (RM8551 - 4.3 Cu ft). I find it only happens after a day on the road, so i think that driving on bumpy roads causes crud in the propane line to get loosened and get pushed up against the orifice, which will block the propane flow. I usually go to the trouble to remove the orifice and give it a cleaning in alcohol. I have always found some brown bits of debris on it, when there is poor cooling performance. Today, I tried a compressed air spray against the orifice, from the burner tube side, to see if that can unblock the orifice without removing it from the fridge.

I will try to depressurize the propane line and knock on the solenoid next time the fridge warms up on propane to see if that helps.

My current theory is that any crud in the line may get dislodged if the propane in the line is shut off, and the fridge will cool again on propane, but it is still there and will block the orifice at a later date. But if I can get a quick fix to get my fridge working while on the road, I am all ears.

[Ron in BC]

I agree that propane can have impurities and I have seen specs of material large enough to block the orifice. But the 8551 seems to have more problems than other models so I do suspect that the solenoid is probably causing a problem in some of the cases.

If I've had poor cooling and checked the flame it was always lit. But I suspect that it wasn't "full size". This could be a result of the solenoid sticking and not fully opening.

At any rate it's faster and easier to relieve the back pressure on the solenoid than disassembling the orifice. That's easy to do by closing the gas valve and removing the test port plug. That's located where the clear plastic tube from my manometer is attached.

Ron

[MyronL]

My RM8551 looks different. Is this that test port plug?

[PGDriver]

Morning Myron yes that is the test port.

[sunrisetrucker]

Ron:
I've been thinking of getting a manometer, are you happy with the one you bought, would you buy it again?

[Ron in BC]

I'm happy with it. I've cross checked the readings with another one and it seems very accurate and, yes, I'd buy the same again.

Very handy for checking what you have or setting up the pressure on a new regulator.

Ron

[Kingfish]

About 8-10 feet of 5/16 clear tubing taped or zip tied to a yardstick works perfectly also.
Simple to make and materials are readily available at Lowes, Home Depot, etc.