Oil in propane line

I've heard about it a few times on here. Apparently there is some kind of oil that gets introduced into the propane tanks and it can migrate into the lines over time. I guess the only fix is to do as you did and blow it out.

are you sure it is oil? it might be liquid propane.

Since your water heater is supplied via the regulator from the VAPOR port, the only way long hydrocarbon contaminants can get in those lines is if the tank is overfilled. If liquid reaches the regulator, sure, you can get contaminants.

This is also an issue for liquid LP appliances.

Oil residues plugging propane lines has been a topic of discussion for years. Even the big boy propane companies can't agree on exactly where they come from. Here's a link to one discussion on the subject if anyone's interested.

Most of that discussion has to do with other uses than in RV's, but there's one point made that's worth paying attention to.

IMPCO wrote:
During the process of vaporization some heavy ends will collect within the regulator over time. This can be reduced by mounting the regulator with the outlet pointed down

That's evidently one reason the regulators are meant to be installed pointing down, and checking for proper positioning is well worth doing.

havent seen that problem in many years. its said by some to be grease forced out of the rubber material in the hoses. who knows.
the repair is to detach the lines, as needed for access, force a small wire thru the steel lines and attach some type of wiper on the end of the wire. this will wipe the lines clean. ive done it, and its a real pain. takes several times to get it clean. the rubber lines will also need to be cleaned.
as always, leak test when the pipes are reconnected and pressurized.

I had it happen years ago while running a portable Coleman heater that was designed to run on 1 lb bottles, but I was running it on a genuine propane hose from a 16 gal(?) cylinder, and I was running it continuously. I don't remember it giving any trouble while burning, but when I changed the first bottle, I remember the mess of pitch black oil that came dripping out of the hose, and the heater. I remember cleaning it all out,.....only to have it happen all over again on the next tank. At that time, it was said that the oil comes out of the rubber hose, which I did not believe a word of. It would have been impossible for that much oil to come out of that hose,....never happened ! I believe it was in the propane.
But, I have NEVER had it happen again either. Ironically, I've never used "propane hose" (whatever that mite mean) since then either.

wally-eye wrote:
Anyone ever had oil in a propane line? I was having issues getting my water heater to light on propane and took the gas line off and it had a bunch of oil in it plugging the line. Once I blew the line out the water heater started right up. Very strange but a simple fix once I figured it out.

Yes, I have had a personal experience with a fellow traveller in a 5th Wheel. We were both south bound and camping next to each other in Mesquite NV in October.

His symptoms were that the furnace would work during the day when the furnace was not needed but would not work at night when he needed the heat.

Long story short, oil had accumulated in a trap in the copper line to the furnace.

Here's some more discussion on topic:Propane hose conditioningThis PDF document includes a photo of the oily residue accumulated from plasticizers leached from propane hoses.

Situation normal. My propane lines in my home have drip nipples just for that reason. The oil is a by-product of the processing.

john&bet wrote:
Situation normal. My propane lines in my home have drip nipples just for that reason. The oil is a by-product of the processing.

I'll buy that story, except it is not in all processing, in fact it is seldom in processing. Or at least I have not seen any sign of oil in any propane line, steel or rubber or plastic in the last 20 yrs.