Foretravel Owners' Forum

Foretravel Motorhome Forums => Foretravel Tech Talk => Topic started by: Cape Bretoner on August 01, 2024, 10:39:51 am

Title: Propane trouble
Post by: Cape Bretoner on August 01, 2024, 10:39:51 am
Having problem with our fridge on propane. Having fridge checked out they said low pressure from propane line. Problem seems to be from the tank or line going to the fridge. When u turn the propane on you hear a gargling noise .has anyone heard of this before. Stove , furnace are working good and fridge works good on electric
Title: Re: Propane trouble
Post by: wolfe10 on August 01, 2024, 10:44:40 am
Propane regulators are not that expensive.

Particularly if over 5-6 years old, just replace it.

If you see any sign of oil in the line when you replace the regulator, use compressed air to blow out the line.  Yes, then it will take a few minutes to purge the air out of the lines.
Title: Re: Propane trouble
Post by: dsd on August 01, 2024, 11:05:21 am
Brett is spot on. I had never operated an absorption refrigerator prior to our foretravel. I had never heard of propane accumulating a liquid in the lines. Kind of like tar??? I would not hesitate to shut the main valve off and open up the lines and flush them out with brake clean. I would follow up by blowing them out real well with compressed air until they're 100% dry. I also found that there is a filter, going into the propane valve on the refrigerator. Mine was filled with that gunk tar and I was able to pull it out of the filter, clean it and reinstall it. You are supposed to replace the valve I did not. Although not required I definitely would consider getting the tank cleaned and re-hydrostatic tested, on propane tanks, it's just a visual inspection for corrosion inside and recertified. Obviously you would want to do that when it was empty lol. ultrasonic leak detector would help you find the low spot that has the fluid pooled in it.
Internet search found

Oil Contamination In LP Gas Systems - Escapees RV Club (https://escapees.com/oil-contamination-in-lp-gas-systems/#:~:text=The%20oil%20contamination%20can%20be,for%20the%20solvent%20to%20evaporate).

Oil contamination can be a problem in LP gas systems. It is introduced during a fill of the LP bottle, and the oil can plug jets and filters in the LP system. Oil in the LP system is particularly dangerous for Dometic or Norcold refrigerators because they have a filter in the SOV valve, and the gas jet is very small. Oil accumulation in the LP jet or filter can result in the fridge cooling unit boiler overheating, and only the Fridge DefendĀ® by ARP can protect the fridge if this happens. The oil contamination can be cleaned out of the system by disassembly and flushing with 91 percent isopropyl alcohol. Acetone can also be used to clean the pipes, but you must not let it touch any rubber or plastic parts. Be sure to leave the LP system open long enough for the solvent to evaporate. If you know that you have oil contamination in an LP bottle, when the bottle is empty the valve can be removed, and the tank can be turned over to flush and drain the oil.
Title: Re: Propane trouble
Post by: Cape Bretoner on August 02, 2024, 07:57:44 am
Up date I removed the propane supply line from the propane tank to the top of the regulator all looked good and then removed the regulator From the elbow  which the elbow and propane hose are mounted to the wall with a clamp. the elbow was filled flush with oil.  the propane hose coming off the elbow at the bottom of the regulator goes up  to the propane manifold or tees.the oil from the propane had settle to the lowest point of the hose which is at the elbow it had about four ounces of oil which was restricting the flow of propane after the regulator. So as wolf and Scott  suggested I flushed the line out with brake fluid cleaner after disconnecting line off fridge and then blow it back with air from motor coach there was no sign of oil in the line from the fridge to the manifold just at the bottom elbow at the regulator and after I blow air through the other lines I  installed a new regulator. fridge is working perfectly hope there is no more oil in the tank.


Title: Re: Propane trouble
Post by: dsd on August 02, 2024, 08:17:56 am
If there is oil in the lines it had to come  from somewhere. I'm sure there is oil in the tank, but more concerned about any moisture quietly causing corrosion. Be nice to run the tank dry and get it checked? If the partial filled tank was removed I wonder if you could roll it over to put the vent valve on the bottom and drain oil? Could also get junk under the valve seat and cause a leak? So for oil to get drawn in it would have to be near the bottom of the pick up tube in the tank I would think?
Caution liquid propane will cause severe burns!
Title: Re: Propane trouble
Post by: Chuck & Jeannie on August 02, 2024, 09:47:53 am
This subject pops up occasionally on this Forum.  The post linked below refers back to even older Forum posts on this topic, and just happened to include the same Escapees Club reference citied by Scott in Reply #2.

Oil Accumulation in Propane System (https://www.foreforums.com/index.php?topic=40088.msg396523#msg396523)

Title: Re: Propane trouble
Post by: Rich Bowman on August 02, 2024, 12:04:56 pm
So I decided to check mine.  Went out and found that it had a drain plug in the elbow.  Got probably 2-3 tablespoons of oil.  I have had a problem in the past with oil clogging the regulator on my Weber grill.  I have a hose that feeds from the on-board propane tank to the grill.

Decided to check the line from the tank to the regulator because of the low point in the loop.  In the process of taking the line off, managed to break a fitting in the plumbing.  I hate plumbing!

Now off to find replacement parts.  And, there was no sign of any oil in the hose on the high pressure side of the regulator.

Rich

Title: Re: Propane trouble
Post by: Chuck & Jeannie on August 02, 2024, 12:50:13 pm
Went out and found that it had a drain plug in the elbow.  Got probably 2-3 tablespoons of oil.
And, there was no sign of any oil in the hose on the high pressure side of the regulator.
This fits with my understanding of how this oil usually shows up.  In most cases I have read about, the oil (if any) is found in the first "low spot" downstream (on the low pressure side) of the regulator.  If there is a drain plug at the bottom end of the hard pipe manifold, look there.  Our coach does not have the drain plug, so in our case the "low spot" is the rubber hose between the regulator and the brass manifold (see photo).  When I disconnected the hose and looked there (10 years ago) I did find a small quantity (less than a teaspoon) of the mystery oil.

This isn't something to lose sleep over, but if an owner has never checked for propane oil accumulation, it is a worthwhile way to spend a little free time.  :thumbsup:


Title: Re: Propane trouble
Post by: John44 on August 02, 2024, 01:01:16 pm
I noticed Mr. Rich has a metric adjustable wrench.
Title: Re: Propane trouble
Post by: Chuck & Jeannie on August 02, 2024, 01:46:45 pm
I noticed Mr. Rich has a metric adjustable wrench.
...and a well used ball pein hammer.  Two essential tools!
Title: Re: Propane trouble
Post by: rbark on August 02, 2024, 03:30:43 pm
Probably why the fitting broke🤣
Title: Re: Propane trouble
Post by: Pamela & Mike on August 02, 2024, 03:34:09 pm

After retirement what is that?

Mike
Title: Re: Propane trouble
Post by: Chuck & Jeannie on August 02, 2024, 03:56:58 pm
"Free Time".  That's when you work your a$$ off and don't get paid.
Title: Re: Propane trouble
Post by: Rich Bowman on August 02, 2024, 04:29:58 pm
I have now managed to find the parts so that I can replace the two damaged ones with only tree new pieces.  Did I mention "I hate plumbing."

Rich
Title: Re: Propane trouble
Post by: Cape Bretoner on August 03, 2024, 07:53:57 am


This isn't something to lose sleep over, but if an owner has never checked for propane oil accumulation, it is a worthwhile way to spend a little free time.  :thumb sup:


This was a problem, drove all day with refrigerator on AC generator running.  stop for the night shut down generator. fridge came on propane, but wasn't working  properly it only had half the propane pressure going to refrigerator the oil in the propane line was restricting the flow of propane And now that I look back and realized that when  I turned the propane valve on at the tank it would starting this gurgling sound coming from the tank. It was the propane, forcing itself through the line . My point is 10 hours later after stopping and a good night sleep  We open the  fridge. Food was spoiled it was a grocery the wife had just done to start this trip  open fridge in the morning and fridge at 70 degrees and then took another 8 hours to diagnose and repaired had to drive to to refrigeration shop, check fridge  OK and then diagnose propane problem and refrigeration shop did not want to work on the propane supply system They said they weren't license to work on propane systems. So i had to figure out next step so i got on the forums and was pointed in the right direction.
Thanks again