Propane flow problem when it's cold

[Kcoldani]

I own a 2003 Winnebago Itasca Spirit 32' Class C
I have had it in the shop over 6 times and the dealer can't seem to fix the problem.
When the temperature drops to around 40 degrees, all propane stops flowing. I can go outside and pour water on the regulator by the tank and it clears up. The regulator has been replaced 3 times, the tank has been removed and evacuated, the thermostat for the heater has been replaced, etc. I'm at my wits end. Problem is that here in California, the shop can't duplicate the problem because the temp rarely gets down that low during the day.
About the water on the regulator: I can turn on my stove and light a burner to get only a trickle of propane. The burner is only barely lit, yet turned alll the way up. When I go outside to pour the water on the regulator, the stove burns full flame immediately and everything else comes on as well. Winnebago Customer Service doesn't have any ideas either. I can't bare another freezing cold night without my heater!!! Please help someone!

 

[Ron]

Sounds like a regulator problem to me.  Are you sure the dealer has actually replaced the regulator with a new one? Is there a different dealer near you that you can take it to?

 

[Alaskansnowbirds]

SNIP  The regulator has been replaced 3 times, the tank has been removed and evacuated, SNIP

Kcoldani,

Was the tank tested in the same position that it sits in the RV? Sounds like you may be getting liquid propane into the regulator that is freezing the regulator up. If the pickup tube in the tank is in the wrong position this could happen. Yet if this is the cause I don't know why it would only happen at less than 40 degrees.

 

[Karl]

After you pour water on the regulator, will you continue to get gas for as long as you want, or does it slow down and stop after a while? When they replaced the regulator, did they check or replace the electric shut-off solenoid(if installed)? If you have one, you might try cycling it on and off several times to free it up. For the short term, you might try placing a 75 or 100 watt trouble light under the tank (at least 12" below it) for a little heat. That may do the trick on a temporary basis. Make sure you keep it well away from any piping or wiring, protect it from water dripping on the bulb and shattering it, and if there's even a remote possibility of a leak, don't do it! Better to be a little chilled than totally fried!

 

[fredethomas]

Could it be oil trapped in the flex line that comes out of the regulator, loops downward a little and then up to where it connects with the iron piping?  I just changed a requlator that was full of oil.  Could be that a slug of it got in the rubber hose and the hot water loosens up the oil.

 

[Tom]

Where does the oil come from Fred?

 

[John From Detroit]

About the water on the regulator: I can turn on my stove and light a burner to get only a trickle of propane. The burner is only barely lit, yet turned alll the way up. When I go outside to pour the water on the regulator, the stove burns full flame immediately and everything else comes on as well. Winnebago Customer Service doesn't have any ideas either. I can't bare another freezing cold night without my heater!!! Please help someone!

I agree with RON, Suggestion, Take a dab of paint, your choice of "invisible" (Ultra violet) or regular paint, Dab it on the outside of the regulator,  Then after the dealer "Replaces" the regulator, check for the paint, If it's there report the dealer to winnabago and to the state department of motor vehicles where he does business.  He won't much like that, he is notified when a complaint is filed against him, but saying you did work when you really did not do it.. They have a name for that.... FRAUD, criminal FRAUD

 

[Gary RV_Wizard]

If your "propane" has a substantial percentage of butane in it, it couldl freeze up around the temps.  LPG is a blended fuel and they often add quite a bit of butane in warm climates. However, butane higher freeze point than pure propane.

You might try getting your propane from a different supplier if you have been using the same one regularly.

 

[John From Detroit]

If your "propane" has a substantial percentage of butane in it, it couldl freeze up around the temps.  LPG is a blended fuel and they often add quite a bit of butane in warm climates. However, butane higher freeze point than pure propane.

You might try getting your propane from a different supplier if you have been using the same one regularly.

I thought of that but LP gas is supposed to be good to 40 BELOW (your choice of C or F) n ot 40 above or so they told us one day when it hit 50(F) below out here... That was a fun day, Father was giving his annual "State of the parish" speech, where he explained that though the parish had gone many many years w/o borrowing any money, they had had to borrow to build a steam plant when the power company decomissioned the steam plant that served much of the downtown area... He went on to explain that due to a small land sale, land that was of no use to the church and in fact was more of a liability than asset, till Greyhound eyed it that is.  They had repaid the loan and had money left over... The punch line was "The boilers are paid for, they don't work, but they are paid for" yes, folkd tempertures around 40 to 50 below on the (f) scale... That was one CHILLY service.

I vote for a regulator issue, if it was the gas itself getting too cold in the bottle it would take more than pouring water on the regulator

 

[Karl]

Word of caution: Regulators have vents to the outside air which allow them to adjust the gas pressure, and must be protected from water, snow, ice, mud, and other things which may clog them. Pouring water over them is NOT a good idea under any circumstances. Water may get inside and completely ruin a regulator. :'(

 

[Kcoldani]

Thank you all so much for your input! I should have posted this a long time ago! I think I'm going to print these posts and take the coach into another dealer (although I've been to 2 already). I shouldn't have to be the one to tell them how to diagnose, but they are clueless.
I too am wondering about the regulator, although the plastic shroud that covers the regulator didn't fit on right after the replacement. That leads me to believe that it was replaced. It was also noted in the work order that the vent was not facing in the correct direction when installed previously. It's odd, when I pour water on the regulator, it doesn't have to be hot, nor does it have to make a lot of contact. I even left the plastic shroud on one time and poured the water over it. It worked. What started me on pouring water on it was from the owners manual. It suggested a lightbulb in the propane compartment if freezing occurs. I don't have a lightbulb fixture to do this, but understood the idea from the warmth. Odd thing is, we're not talking freezing temperatures here.
I do not fill the propane at the same place all the time.
The tank was evacuated (because I too expected moisture in the tank).
The water does seem to do the trick only temporarily, although it's usually morning when I journey out to the tank with my glass of water and it eventually warms anyway. Once when I was in the snow, the water proved to only be temporary. It eventually stopped flowing hours after the water pour.
Any more suggestions would be appreciated. Thanks!!

 

[Gary RV_Wizard]

John,
You are right about the boiling point of propane (-42F or -42C), but the fuel does not vaporize well much below +10-20 F.  Also, the venturi effect as the vapor rapidly flows through the regulator further cools the gas.

Butane's boiling point is about 10 degrees centigrade warmer than pure propane and thus butane perfroms poorly down around freezing. Butane is typically blended with propane in warn climates becasue it perfroms better than propane at higher temps, but if you carry it to a cold climate (e.g. mountains) the blend  can cause problems like this.

Given that the regualtor in this situation has been replaced several times and the tank purged, the fuel seems like a possibility, even if a remote one.

 

[lvshoebxfrd]

This is shure late but here goes,I had a problem like that they purged the tank & added alochol no more freeze ups.I would take it to a dif place & purge again.Don

 

[Karl]

lvshoebxfrd,

If you meant that they used alcohol to purge the tank and lines of water, that would make sense. Alcohol, usually isopropyl, is commonly used in industry for that purpose to allow moisture to evaporate more readily. I don't believe you meant that they added some to the tank and then filled it with propane. That would make the problem worse by adding water; a part of all but 100% alcohols), and by forming carbolic acid (now called phenol) which is both poisonous and corrosive. I just hope they didn't use a good single malt Scotch whiskey ;D

 

[RLSharp]

If you meant that they used alcohol to purge the tank and lines of water, that would make sense. Alcohol, usually isopropyl, is commonly used in industry for that purpose to allow moisture to evaporate more readily.

Karl,

I have heard of adding anhydrous methanol to a propane tank contaminated with water and then filling the tank with propane. The propane, methanol, and water mixture then forms an azeotropic system. When the propane vaporizes the water and methanol also vaporize according to the Gibbs Phase Rule as a three component azeotope. This removes a small percentage of water in the vapor and eventually removes the water. Obviously, you must use anhydrous methanol or as you say you will just add more water. Propane and water do not form an azeotropic system so water in a propane tank just stays there unless a specific chemical is added to allow the Phase Rule to operate.

<<...and by forming carbolic acid (now called phenol) which is both poisonous and corrosive.>>
BTW, there is no way to form phenol from any combination of propane, water, methanol (or isopropanol). Phenol is an aromatic compound (C6H5OH).

Richard

 

[Ron]

Thanks for the clarification Richard.  A flight student I had was in the propane business and he tried to explain this to me but it never took hold.  You have just cleared it up for me.

 

[Karl]

Richard,

My quote

a part of all but 100% alcohols

is in total agreement with your use of anhydrous (without water) alcohol.

I know it's a nit, but beg to differ:

BTW, there is no way to form phenol from any combination of propane, water, methanol (or isopropanol). Phenol is an aromatic compound (C6H5OH).

Isopropyl alcohol (Isopropanol) CH3.CHOH.CH3 and propane CH3.CH2.CH3 can indeed be partially converted into Phenol with heat and a catalyst - most commonly copper, and copper is used in brass gas fittings. I agree that the probability of the conditions required are remote, but possible.

 

[RLSharp]

Karl,

I know it's a nit, but beg to differ:
Isopropyl alcohol (Isopropanol) CH3.CHOH.CH3 and propane CH3.CH2.CH3 can indeed be partially converted into Phenol with heat and a catalyst - most commonly copper, and copper is used in brass gas fittings. I agree that the probability of the conditions required are remote, but possible.

As an organic chemist whose interest and field of expertise in graduate school was reaction mechanisms, I would have to see a proposed mechanism for the formation of phenol from propane and isopropanol before I felt that the reaction was possible. The process of converting an aliphatic hydrocarbon plus a secondary alcohol into an aromatic compound even under catalytic conditions, especially a with low catalytic activity catalyst like copper, is extremely unlikely. I will have to admit it has been 40+ years since I was in graduate school and that catalytic chemistry was not my field of research; in addition, I have forgotten much of what I learned at Purdue. I did have a strong interest in reaction mechanisms and know that creation of aromatic compounds from strictly aliphatic starting materials is extremely difficult, especially under standard conditions of temperature and pressure. If we were talking about very active catalysts such as those found in Periodic Group 8, such as Palladium, Platinium, Rhodium, Ruthenium, etc., I would not be surprised that an aliphatic to aromatic catalytic conversion could be promoted. Even then, for such a reaction to take place in an RV propane system would be extremely interesting (at least, to me ).

The only reason that I even voiced my opinion about the creation of phenol from propane and alcohol was your statement that "... and by forming carbolic acid (now called phenol) which is both poisonous and corrosive." might lead people to believe that an actual, no matter how remote, hazard could exist from water and/or alcohol contaminated propane.

Unless you can give me some specific information on how the above reaction can take place in an RV propane system, I guess we will have to agree to disagree.

Regards,

Richard

 

[Karl]

Richard,

I guess we had different chemistry professors - mine taught at Harvard ;D (Iron oxide would have been a better example of the catalyst)

To everyone out there who read my post and was concerned: The probability of that happening is quite low; so low that it can be ignored for all practical purposes. I apologize if my ranting caused any of you to be worried. The process by which this could occur requires much more heat than you will ever encounter during your travels.

Regards also,

Karl

 

[Ned]

Maybe he taught at the Harvard Business School