Propane line noise - Montana Owners Club

N5PHT · 09-15-2013, 12:22 PM

Our HC 343RL emptied a tank of propane and when it switched to the other tank a loud 'whine' appeared. I shut off the propane on both sides and moved the empty tank to the opposite side and hooked up the full tank to the 'primary' side (where the auto switch over is located) and all is fine again. Could it be the little red regulator on the side I tried to use? The pigtail line is new on both sides.

Ideas appreciated.

jimcol · 09-15-2013, 12:45 PM

Those little red regulators have been known to go bad. Mine did. I just removed it and have not had a problem. If I had your unit I would move the tank back to the original side, put a demand on the tank and listen for the noise. If it makes the noise sometimes you can feel the regulator and tell it is the source. Sometimes a rap on the regulator with a wrench will stop the noise. Let us know! Jim

richfaa · 09-15-2013, 01:48 PM

My 2006 3400 did that and it was said the red regulator was the cause of the problem. I changed it out for a better one and it did not solve the problem. It seemed to do it when the tank was near empty after a while it never did it again. This 2013 has not done it thus far.

denhammkc · 10-02-2017, 10:13 AM

I know this is an old thread but:
I have a 2017 and the RED regulator on the door side makes a high pitched wine when in use.

Can I just remove it?
I know the line crosses the RV into the auto change over / regulator on the off door side. I would not think it was necessary.

rohrmann · 10-02-2017, 11:23 AM

I've previously posted this explanation why the red regulator is there. The whine or whistle does not hurt anything. I've had this happen on the propane grill as well as on both sides of the rig from the propane system. The explanation was copied from another forum, do not remember which, but Keystone or any of the other manufacturers would not be spending the money or time to install one if it was not required for safety.

The main reason for the red regulator is to make sure that once the propane leaves the tank as a vapor that it stays a vapor. Propane regulators in trailers do not regulate liquid only vapor. If the regulator was not there the pressure in the hose/pipe would be the same as the tank. This could lead to the vapor condensing back into a liquid. With a reduction in the pressure from the regulator to the other side of the coach this will greatly reduce the possibility of the vapor in the crossover hose/pipe turning back into a liquid. This is all based on propane’s vapor/pressure saturation points. The lower the pressure the lower the temperature to turn it back into a liquid.

beeje · 10-03-2017, 09:12 AM

I think I have a similer problem. When one tank gets near empty it will not switch over to the other. The water hater starts to gasp for propane and sets off the propane detector. If I switch the tanks all is well. Have not really tried to figure out what is wroung.

twindman · 10-03-2017, 04:48 PM

Quote:

Originally Posted by beeje

I think I have a similer problem. When one tank gets near empty it will not switch over to the other. The water hater starts to gasp for propane and sets off the propane detector. If I switch the tanks all is well. Have not really tried to figure out what is wroung.

Hey, I had this same issue this summer. Heard a whine with propane, but eventually ignored it. At some point something started leaking propane and kitchen smelled really bad. With the stove, frig and water heater close together, I couldn't tell what was leaking. Shut down everything, waited an hour and it smelled bad again. Aired out and waited overnight and had no issues for the next 20 or so days and then was home.
Thanks for this info, as this has happened twice and I hadn't heard an explanation or solution.

**Carl n Susan** · 10-03-2017, 06:06 PM

It is conceivable what you are observing is somewhat normal, particularly if the Propane Detector is silent. When my propane tank connected to the red regulator (ODS in my 2012) gets close to empty there is a noticeable whine. An irritant but not a big problem to me as shortly thereafter the tank goes empty and the auto switch regulator shifts to the other full tank.

There is sometimes a smell from a gas using device as either tank approaches empty. This is usually due to the perfume agent which sinks to the bottom of the tank. Each time you refill, propane and perfume are added and the new perfume starts sinking towards the bottom. The perfume accumulates over time. When the tank gets low you get more than normal perfume along with the propane. The propane burns, the perfume does not. Consequently you smell the odor and one's first reaction is there is a leak.

If the Propane Detector is silent and the odor goes away after you switch tanks you can assume there is no leak problem. Purge the tank periodically and the perfume will be evacuated.

beeje · 10-04-2017, 08:59 AM

Makes sence. Like you said I do not think I had leak but the detector is so annoying that I mounted a toggle switch next to it so I can turn it off if needed. Its on my list of things to figure out.

BB_TX · 10-04-2017, 09:09 AM

For those who may have missed it, here is an earlier discussion on the why of the red regulator valve.

http://www.montanaowners.com/forums/...egulator+valve

Twopetes · 10-04-2017, 03:03 PM

Just to add my 2 cents, about this time last year, the furnace in our 15- HC 353 would not start (sometimes). I checked a lot of stuff and finally took it to my local RV shop. They changed the sail switch and igniter and the furnace seemed to work, but they tested overnight - and "no joy". They finally changed the "little red" regulator, and now all is good. It was less than 2 years old and really was not used that much - so they do go bad!

jcurtis934 · 10-04-2017, 07:00 PM

That regulator...a high pressure 30 psi regulator...is needed. Mine went out this year leaking out the top surface where it is crimped all around and so did my auto changeover valve. Trip to LA Mesa rv in albuquerque rewarded me with new ones and better than what was installed.

psomers · 10-06-2017, 02:08 PM

Sorry about hi-jacking this thread but have related question. At a recent camp out propane questions were argued. Question #1, can an empty bottle be filled with out opening the bleeder valve? #2, can a bottle be over filled if the bleeder valve is open? #3, at average temperature what is tank pressure/ #4, what temperature does propane boil to vapor at 30 psi?

I have researched and there is a lot of information out there. These are some question I not sure of.

Lenny K · 10-06-2017, 05:31 PM

You can fill by weight which is the only way it is done in Canada. Never heard of opening the bleeder valve until I went to Arizona. Sure is the lazy man's way of filling a tank and you're the one paying for the propane going out of the valve.

denhammkc · 11-05-2017, 06:20 AM

Thanks for all the updated comments. I replaced the red regulator and no more noise. The OEM regulator would make the noise regardless of how full the tank was.

P.S. I just switched out my 30 lb tanks for 40 lb tanks that I got new at local big box hardware store for $71 each. They fit just fine I only had to raise the locking strap to a point above the mid point of the tank to keep it firmly secured.

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