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-   -   Odd propane behavior - starts out ok, then gets weak... (https://www.forestriverforums.com/forums/f224/odd-propane-behavior-starts-out-ok-then-gets-weak-171912.html)

brucemc 10-08-2018 03:16 PM

Odd propane behavior - starts out ok, then gets weak...
 
My son purchased a new 2019 No Boundaries 16.5 trailer a couple of weeks ago. He's been puttering on it, including spending a few nights to get familiar with it.

A couple of days ago, he noted the furnace was making odd noises., like it was sputtering.

In testing today (where the outside temperatures are around 60) we can look through the vents at a peep hole to watch the flame. Initially, the flame is bright blue and runs 5 minutes or so, but then starts turning yellow/orange, which coincides with the odd sound.
We found not only the furnace would do this, but the cooktop and water heater. In fact, it takes only 5-10 seconds for the water heater to sputter out & go into fault for lack of propane.

His unit has a 20lb propane bottle, which has a bit less than a 1/4 remaining. We swapped tanks for a 30lb of mine which is 1/3 full.
On both bottles (cylinders), we would open the valve very slowly to ensure the internal check valve wouldn't engage.

Same behavior.

Suspecting the regulator, I pulled mine out of my Sunseeker, and swapped it out. We didn't use his Acme nut/pigtail, as mine has a POL nut on the inlet.
At this point, we had bypassed his tank, pigtail and regulator.

Same behavior.

The lines are fairly large so there's lots of capacity. All tees are visible, where the lead in connects to an aluminum pass-thorugh tee with two taps, then carries on to the next pass-through tee with two taps.

The next test will be to fill the bottle to ensure it's not a case of a low bottle. (I have two more for the grill which need filling, so it's a good time to go get gas... this afternoon)

In my experience, I've never had issues like this with a low bottle - when there's liquid gas, there's sufficient vapor. When the liquid is gone, there's no more gas. Plus, we've bypassed 3 of the main causes of this issue.

He'll call & make an appointment for service, but in the mean time, I'm turning to the RV community to ask if anyone else has experienced such an issue, or if you have ideas beyond what we've already tried.

wildcatter 10-08-2018 03:25 PM

This isn't a propane issue, it as an oxygen (or lack of) problem, if it is doing it on all the gas appliance I would look at what jets were installed or if they need to be adjusted. I had a similar problem with my house gas range and had to adjust the gas jet to allow for more air (oxygen).

wmtire 10-08-2018 03:38 PM

I am assuming you are weighing the cylinders to ascertain how much propane is left in them ?

60 degrees shouldn't affect the operation of , like you may see in more near freezing temps that may possibly have a more butane/propane mix in the cylinder that you sometimes get from some places. We've seen that cause problems, but in colder temps.

I would get the cylinders refilled as you stated, then go from there if the problem still occurs . At least then you can eliminate that possibility from the list... And you said you needed them refilled anyway for other things

brucemc 10-08-2018 03:38 PM

Interesting theory, Wildcatter.



I was there when we went through the pre-delivery inspection. The fella ignited the furnace & stove top, but didn't light off the water heater (that I was aware of, anyway). Perhaps this may have become apparent at that time.


However, in the mean time, he had spent 3-4 nights in the unit w/o issue, so it would seem to me this is a new issue, a week after delivery.


That's why this puzzles me so much. These are off the shelf components, so it's inconceivable they all would have the incorrect orifices. (The other possibility borders on conspiracy.... that there darn'd gmt of our is stealing all the oxygen!)

brucemc 10-08-2018 03:43 PM

Quote:

Originally Posted by wmtire (Post 1945542)
I am assuming you are weighing the cylinders to ascertain how much propane is left in them ?
...
I would get the cylinders refilled as you stated, then go from there if the problem still occurs . At least then you can eliminate that possibility from the list... And you said you needed them refilled anyway for other things


No, we didn't weigh them, but that's certainly a possibility with the 20 pounder. The 30, on the other hand, was heavy, and if I hoisted it up a bit, wiggled it, then let it hang in my hands, it would continue wiggling around as the liquid sloshed around.


I'll update this thread in the morning after refilling the cylinders.



Any other ideas?

Chuck_S 10-08-2018 03:51 PM

Check the inlet and exhaust vents on the outside wall. Wasps and spiders love to build nests in them and this can starve the furnace of the air needed for combustion.

-- Chuck

wmtire 10-08-2018 03:57 PM

I'm trying to wrap my head around if possibly a loose fitting that might could leak propane , could also possibly then suck air in when an appliance was turned on downstream of it. Kind of like a Venturi effect.

brucemc 10-08-2018 04:07 PM

Quote:

Originally Posted by Chuck_S (Post 1945551)
Check the inlet and exhaust vents on the outside wall. Wasps and spiders love to build nests in them and this can starve the furnace of the air needed for combustion.

-- Chuck


All is clean. That's one of the areas I checked yesterday. We are dealing with a swarm of stink bugs, but nothing was in either the furnace or WH's venturi tubes.



That's what is so crazy about this issue - Furnace, cooktop, and water heater. It's gotta be a delivery issue, somehow.



wmtire - yea, that thought has been on my mind as well. Yet, the issue has to exist prior to, or at the first tee (technically, a manifold), as both the WH and furnace are tapped off of that point. The second tee is the source for the stovetop and refer.

brucemc 10-08-2018 06:27 PM

My Bottles:
Empty is 17lbs
Nearly empty is 19lbs.


My son's bottle:
32lbs. (hmmm)


Back from the gas outfit:
Now 35 & 37lbs.


Thus, his was only about 4 lbs down. (so much for estimating by feel!)


And the 30 pounder feels like a full 20 pounder.



Results: The same behavior.


Next, we'll check if there is oil settling at the bottom of a low point, as suggested by someone on RV.net, and other posts I've seen.

gasman6674 10-09-2018 09:40 AM

New trailer correct? Disconnect the line from the regulator to the first tee and check for trash/tape etc. That would be the common failure point for all the appliances. If you can get a manometer or a 0-35" pressure gauge and see what the delivery pressure is at the appliances, should be at least 10" wc 11-11.5 would be better. Check where the line connects to the appliance not after the controls. You will probably have to do some adapting so you can check flow pressure. Good Luck

DouglasReid 10-09-2018 03:00 PM

Was the propane bottle full when you bought the camper or did you have it filled yoruself. Many people do not realize that a new propane bottle has to be "purged" of the air in it from the manufacturing process.

This entails adding an amount of propane to the bottle and then venting it til it is nearly empty. This removes the air and fills it with pure propane.

The symptoms of an unpurged bottle are what you are experiencing, sputtering and inconsistent flames.

You can test this if you have another propane bottle that you know to be working well. Switch them and see if the problem goes away.

It could also be the Acme connection device causing inconsistent gas flow.

Bama Rambler 10-09-2018 03:40 PM

I'm thinking a pinched or mostly blocked line near the front that pressures up when everything is off and then slowly starves the appliances when you light them due to the pinch or partial blockage restricting the flow. Especially since you've eliminated all of the normal items.

KyDan 10-09-2018 03:48 PM

It's not a jet issue as mentioned earlier... they start out blue flame so the jets are good.

ICanFixIt 10-09-2018 05:19 PM

I'm with Bama Rambler. If you're sure your regulator is fine, then check for a kink, pinch or obstruction in the line or a connection. See if you can test by bypassing as much of the line as possible by connecting as close to one of the appliances as possible to test the flow and then work your way back.

emoney 10-09-2018 05:26 PM

Yikes, no hints but I sure hope they find the issue. Iíve heard of that oil settling thing but that affecting every appliance and not until 5 mins after using each one really is a puzzler.

brucemc 10-09-2018 07:11 PM

I'm inclined to agree with Bama Rambler regarding a partially blocked line, considering we connected a known good 30 pound bottle via the known good regulator out of my 3 year old sunseeker, and still experienced the same symptoms.

Yes, a very new trailer....

Emoney, I agree - the unit is too new to see the oil issue, I feel. My son has burned only 3 lbs of the propane supplied by the dealer.

Yes, it was a new bottle, but supplied and filled by the dealer. Additionally, as I noted above, we also tried the known good 30 lb cylinder as a test, and it certainly has plenty of remaining fuel at 2/3's full.

More later... Thanks everyone!

brucemc 10-09-2018 10:34 PM

I removed the lead in hose from the regulator output to the first manifold, and found ... nothing. It was clear, as was the manifold.

Next, a nod to wmtire:
Quote:

Originally Posted by wmtire (Post 1945559)
I'm trying to wrap my head around if possibly a loose fitting that might could leak propane , could also possibly then suck air in when an appliance was turned on downstream of it. Kind of like a Venturi effect.

Then, I found the issue with the water heater shutting off in 5 seconds. The gas connection at the control valve was only finger tight. I tightened the fitting and re-installed the lead in hose, the lit the system off. The water heat ran w/o issue, so I lit off the cooktop and furnace. They ran nicely...

All looked good for about 15 minutes, then the furnace started making noise again. The nice blue flame along the burner had dropped off significantly, and the cooktop flames slowly turned orange.

Again.

I checked the input hoses to the furnace and refer, both are nice and tight. I hadn't had a chance to check the connection to the cooktop.

My son should have an appointment with the service department soon. Had I not found the issue with the WH, they probably would have found that, checked things for 5 minutes, then said it was fixed.

If this wasn't under warranty, then I'd keep working on it until I resolved the issue(s). As it is still under warranty, I'd like to see what they find.

Reverse_snowbird 10-09-2018 11:02 PM

We had similar problems, but our propane tank is not removable. When we went to have it refilled at a propane dealer, he found that a pressure relief valve hadn't been turned on. Turned it on, refilled the propane and no problems.
Unfortunately, it sounds like you've got a different problem.

Villagerjjm 10-10-2018 03:01 PM

I would suspect condensation in the propane supply line. I would use a pressure blower on the lines.

dbledan 10-15-2018 10:48 PM

Hmm. I am having very similar issues. Started when in Yellowstone out of warrenty and I thought maybe it was altitude as the secondary tank worked for a bit and then had the same problem. When I got home things worked fine for a little while then repeated itself after a few hours.

This last trip was at home and my furnace and water heater were doing what you are describing but only when running at the same time. I thought it was the regulator so I replaced that. It seemed to resolve issues with the fluttering. I ran a tank completely out and it would not switch to the other tank. I swapped the pigtails and it worked again. I ordered new pigtails to fix that.

Based on your experience I will check on the fittings to see if they are drawing air or are lose. Someone thought condensation in the line which I think I will check for as well. You seem to have eliminated many things I have plus a few more so I am at a loss for next steps. Mine could end up being a few different issues that made it harder to figure out. Yours seems more consistent and you have replaced more items with known working pieces.

Let us know what you find and I will let you know if mine was unrelated. If the new pigtails work I had different problems.


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