Propane hell

[DirtyDog]

I have a new tank and I'm going to be reading all the details in this thread and see if I can get this figured out in the next few days. However I have one question now - when you guys say "green acme nut" - do you mean the plastic nut that screws to the propane tank valve? Does it actually say "Acme" on it somewhere?

 

[Alaskan Snowbirds]

Green Acme Nut

Dog,

That's what I mean and I haven't looked to see if it says that. It's the only "green nut" in the camper I could find (I'm bald and Susan's kind of a dishwater grey and the rest of the nuts are pretty much chrome or stainless. I'd go check it but it's been a long day of fishing starting at 4AM and I'm well into the happy hour so I might get lost. I'll check tomorrow, if I'm in better shape

From everything I've read and seen that big green sucker is "the" acme nut.

I stopped in at the local Amerigas dealer yesterday and had them purge ($7) and fill ($3.50/4.50 gal...remind me to fill up before we come back to Juneau next year!) the tank, just for good luck. Also talked to them about getting an "old style" hose with non-limiting nut and they said no problem, just bring the other one in so they can see what kind of thread it has at the regulator end (1/4" NPT or something else I didn't retain). They don't have stock lengths and will custom make one for me.

I'm really curious to see how the new tank works out for you!

Happy Trails!
'birds

 

[chnlisle]

Acorn Nut

Here's one

 

[keith]

I believe the green nut is called acme is because the threads are acme threads. Flat on the top and bottom and a little steeper angle on the thread. A much stronger and less likely to back off thread style.

 

[Stan@FourWheel]

Hey DirtyDog


Let me know how it goes and what you find out ??

In the shop they could get your camper to do the "low propane flow" thing every time when they wanted it to (during the trip where our driver came and got your camper and we had it here in Woodland).

But at the same time, the guys in the shop could also get it to run for days without any problems at all, by doing just one thing.

If they opened up the propane tank and jumped in the camper and tried to light the stove or furnace, etc., enough time had not passed to allow the pressure to build up in the outside propane line (ACME nut) to allow the small check valve to fully open and allow the full flow of propane to the camper appliances.

But, if they opened the propane tank up, waited a few minutes, and then hoped inside the camper, the system worked every single time. At least from what they could tell in the shop playing with it for those few days.

At first we thought it was a bad ACME nut (hose), but the mobile RV repair guy you called and had come to your place in Bend, installed a new / longer outside propane hose on the camper for you (I think) ??

That is the part that really stumped us. Your camper at that point had 2 different hoses used on it at different times.

I hope the new propane tank works !!

Let me know if it does not and we can go to plan C to get it working for you ASAP


thanks for your patience





.

 

[Stan@FourWheel]

here is some information on how that check valve works ...




.

 

[mtnman]

Thanks for the post Stan. The spec sheet for the CGA 791 connection describes perfectly what to expect operationally from the propane system. This is exactly what I am experiencing with my Hawk. If I turn-on my tank valve (after the system has been sitting for awhile and the pressure in the lines as bled off) and I immediately try to light my cook top, I get the low flow condition. It will not correct itself without turning off the cook top and waiting for awhile. If I turn the tank valve on and wait for a minute or so, I have not seen the problem. In fact, when I turn the valve on and get down close to it and listen, I can hear the connector "click" when the line pressure has equalized and the system is ready for "full-flow" operation.

It would probably save your company and 4 wheel camper owners a lot of grief if you document this situation in your user manuals.

Thanks,
Norm

 

[craig333]

Really makes me glad mine is setup this way.

 

[DirtyDog]

The latter case was always when tank was half full or less and I think the former was too. Could be just coincidence though.


I experienced this too (half full tank and low flow), but not consistently enough to conclude that this is a factor.


Another propane problem I (and another FWC owner I talked to) have is the propane sensor going off with an amber light and loud "chirp" every 30 seconds to a minute or so. Nearly always at 3 AM (arrrrrrrrrrrrrrgh).


Yup me too, on both campers I have had. This is propane problem #2 and the leak seems to be at the valve on the propane tank when it is screwed open.

At what ambient temp are you seeing the problem?

No pattern. It's worked fine at 10 degrees and not at all at 60 degrees.

Because the person seemed to not vent the tank when filling is a good reason to purge the tank of too much air and moisture. Just to make it clear....and helping winter200 make his good points!!!

This is the only factor that makes sense given all the info I have. I'm going to start with a freshly purged and filled propane tank and see what happens.


DD,

I don't know if anyone mentioned this, but on my tank there is a "bleeder" valve located on the tank valve. Usually right under the knob for turning on the gas. It is usually for a small slot head screwdriver. Then there is a very small sized hole next to it (about the size of a small head of a pin). This is for bleeding off the "bad" air (moisture laden) in the tank after EVERY refill. With the tank in the upright position you open the screw valve until you SEE a vapor coming out of the small hole. This is the contaminated air that has moisture in it. let it bleed off until you just hear the hiss, and see no vapor. Then close the small valve. Bleeding off this bad air may solve your problem. I carry my tank horizontally in my hallmark, and after I bleed off the moisture and lay the tank on its side there is nothing but the gas vapor, so you should have no interuption in flow. I hope this helps. If not, you still have the option of a good high cliff!

Good Luck!

Paul

Good info thanks

 

[DirtyDog]

But at the same time, the guys in the shop could also get it to run for days without any problems at all, by doing just one thing.

If they opened up the propane tank and jumped in the camper and tried to light the stove or furnace, etc., enough time had not passed to allow the pressure to build up in the outside propane line (ACME nut) to allow the small check valve to fully open and allow the full flow of propane to the camper appliances.

But, if they opened the propane tank up, waited a few minutes, and then hoped inside the camper, the system worked every single time. At least from what they could tell in the shop playing with it for those few days.
.

Unfortunately simply opening the propane tank valve for a few mins (or even a half an hour) has no bearing on the problem. Also, it worked fine half of one night and then the flow stopped in the middle of the night with a half full propane tank. When I hooked up the BBQ (almost empty) tank to the camper I had full flow immediately and I didn't even wait a few mins.

Thats the exasperating thing about this. There is no pattern or circumstance that suggests a cause for the problem. I'll get the new tank filled this weekend and hope for the best, although the real test will be taking it out for a few days which probably won't happen for a couple of weeks.

 

[DirtyDog]

I couldn't help myself

Ha just saw this

 

[Alaskan Snowbirds]

Rigid Connection?

Really makes me glad mine is setup this way.

craig333,

Your propane "hose" looks like it should take care of any concerns about an ACME nut! Is it set up similar to what it would be in a connection to a home?

Is the plumbing rigid from tank to regulator, or is there flexible hose in the line? If rigid, it seems like there would be some possibility of cracking over time from movement...have you had it set up like that for awhile and used it off road some without problem?

I haven't been into the propane plumbing of the camper other than lighting the hot water heater and hooking up/unhooking the tank but, if I remember correctly, the propane line to the hot water is copper too but a smaller 1/4"(?) diameter, so maybe there isn't a concern about flex in the line...

Thanks!
'birds

 

[HERR42]

how do you fill it?

 

[Alaskan Snowbirds]

Tank Stays?

how do you fill it?

HERR42,

I was thinking that was the slick thing about this...it looks like the cap with retainer comes off and you hook to the line without having to remove the tank...if so that would be a real plus for me.

Happy Trails!
'birds

P.S. After going back and looking at the picture again I don't see a shutoff downline and it looks like the regulator at the bottom left, so maybe that isn't how it works...guess craig333 will let us know!

 

[craig333]

It is rigid to the regulator, but flexible after. You unscrew the fitting to fill the tank, the other fitting is just for hooking up propane appliances.

 

[pods8]

I haven't been into the propane plumbing of the camper other than lighting the hot water heater and hooking up/unhooking the tank but, if I remember correctly, the propane line to the hot water is copper too but a smaller 1/4"(?) diameter, so maybe there isn't a concern about flex in the line...
'birds

FYI: It's 3/8" OD copper tubing inside the camper.

 

[Alaskan Snowbirds]

Ahhh...now I understand.

It is rigid to the regulator, but flexible after. You unscrew the fitting to fill the tank, the other fitting is just for hooking up propane appliances.
Nice setup, thanks for the clarification.

Pods8, thanks for the tube size information. Hope the knee is healed and you're running sprints by now!

'birds

 

[HERR42]

i have used many bbq's that displayed this same issue.

if a burner was left on as the tank valve was opened, the safety valve close and not allow full flow.

close the tank valve. turn off the burner. then open the tank valve...slowly. the safety valve would relax and allow gas flow. opening a burner valve would be ok at this point.

i dont think the safety valve is the issue for Aaron.

 

[Alaskan Snowbirds]

If you can still run the heater, then you have enough voltage - the heater won't light if the voltage is too low. The green LED, if I recall, is about 12.1 volts or above - that's plenty for the sensor.

It sounds like you have a faulty sensor or a wiring problem to the sensor. I have run batteries down to 11.4 volts (then the cut out switch kicks in) and never heard either alarm complain.

The first thing I would do is unscrew the sensor and make sure the wiring looks good - no loose connections, etc. If you have a multi-meter, check the voltage at the sensor next time it complains. Then check your voltage at the 12 volt outlet. The two voltages should be within 0.1 volts.

The 15 min delay is a clue that the problem may be the sensor. The sensor should have only a few second delay before complaining about low voltage as any motor turn-on drops the voltage for only a few seconds.

Jack,

I broke out trusty old multimeter yesterday, pulled out the sensor and found the only spot to check voltage without cutting wires etc was where the crimp fittings connect the sealed propane sensor to the camper wiring. I slipped the multimeter probes into the crimp on fittings and checked the reading and found that I'm lucky to read my old analog multimeter to the nearest volt and .1 volt is out of the question.

I got a pm from Stan on it the other day so it sounds like they're into it now and I'll wait for the upshot of that.

Stan sent a picture of another propane sensor in the pm, so it sounds like there may be at least two different kinds out there. The picture of the other one showed a "mute" button and I'm curious about what that's all about.

Below is a picture of the nasty little bugger I have. The light runs green and it's quiet when it's happy, turns yellow and makes a loud chirp every 30 seconds or so when it's unhappy at 3 AM and I don't know what kind of fuss it kicks up when it gets a whif of propane. It's a lot like Darling Daughter was at 6 mos old.

The scenario is that we hit the sack with the furnace set low and the propane sensor in the green and quiet. The furnace cycles on and off for much of the night with no problem. Then it kicks on and the sensor gets ugly. I pull the fuse and put it back in, with the furnace still running, and the sensor is happy. Then the furnace shuts off and when it cycles back on again the sensor gets ugly again, until I pull the fuse and put it back in again and it goes back to green with the furnace running. I played that game with it for three of four cycles one night just to confirm that it repeats. The battery light was in the green every time I checked it. It seems like it almost has to be a voltage drop at furnace startup (or when the igniter clicks with the fan already running) that offends the sensor and not a fault in the wiring because the wiring fault would be irregular and not be repeatable like this is.

I could probably live with it the way it is if it reset itself back to normal after furnace startup...like it does when I pull the fuse and replace it.

Hopefully FWC will have a fix.

Thanks for the input!
'birds

 

[Alaskan Snowbirds]

P.s.

... I have run batteries down to 11.4 volts (then the cut out switch kicks in) and never heard either alarm complain...

Jack, does your sensor look like the picture I attached to the last post?? When you say "the cut out switch kicks in" is that the cut out switch you installed yourself to keep the batteries from discharging all the way? Was your furnace cycling on and off as the battery got lower? Just trying to confirm that this isn't a normal thing for the same conditions.

Thanks again,
'birds