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JBarca

Radnor, Ohio, USA

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Posted: 10/16/22 10:54am Link  |  Quote  |  Print  |  Notify Moderator

JimK-NY wrote:



Thanks for the reply. Sorry for the delay but I just got out of the hospital. The camper is a Northstar Igloo. I think it was sold as a 2005 model but actually built in 2004. I am positive the HW heater is Atwood. I believe the furnace is also Atwood but cannot check on that or the stove top until I am able to climb stairs in a couple of days. The is no connection for a BBQ grill and the refrigerator is compressor.

I used it a couple of years as a fulltimer but since then it has been stored in the winter outdoors in Long Island, NY. Repairs have been minimal. I replaced the ignitor on the HW heater. I have replaced the pigtails every 2-3 years due to hardening. In addition to replacing the pigtails last month, I also decided to replace the switch over regulator due to age.


Hi Jim,

Hope you are doing well now, no worries on a later reply.

On the older campers, (20 year range +/-) there was a trend at the time by the RV manufacturer's to stick with certain brands for both quality and pricing on what that appliance manufacture offered.

It appears in your case, Atwood Mobile was the choice for the water heater, odds are high the furnace and the range. The fridge and AC unit could be Dometic as they offered both, or they split up in Norcold fridge and Coleman Mach AC.

I do total camper restorations & localized water damage repair as a somewhat extreme retirement hobby. Water damage is the main issue requiring restoration, but I go through every appliance and mechanical running gear etc. in this restore process. Most all these campers are in the 15 to 20 year old range which is about where yours is at. I do not do this for a living, so my sample set is close to 20 campers so far for this information. We have a few RV tech's on the forum who may have lots of years on this to confirm what I have been seeing.

In this restoration process, I normally end up pulling all appliances out of the camper that are mounted in the siding to do a bench test, clean up and repair on all of them. I have to fix the rot, so out comes the siding mounted appliances. When it comes to the LP system, I test each appliance separate and then as a complete system. There are 3 tests to make this complete and I use either a manometer or a precision LP gas gauge. The gauge is quicker, but if a question comes up, I verify it with the manometer.

You could very well have small LP leak or leaks on the appliances. In fact, I have yet to restore a 20 year old vintage camper without some LP gas leak somewhere.

Lets start with the furnace. The gas valve leaking is about a 50/50 issue with a fine leak. This may be aggravated by the camper not being used in a long time. When the outside of the valve has corrosion fuzz on it, odds are not good for it. While the valve tests great for no leaks at the start, once the valve is cycled, tests there after show it does not always seal up tight. See the pics from the bench test.

The fuzz on the outside of the valve.
[image]

The bench test setup using the gas gauge.
[image]

Confirming the leak at the valve
[image]

I even test the new valve before installing. They do work from the start thankfully.
[image]

These RV LP gas valves are not rebuildable, all you can do is replace them. I suspect what happens is, being stored outside in an unheated space, spring time condensation sweat when the metal was cold, then started to warm up, starts the bare aluminum into a corrosion cycle. You being in NY and I am in OH, that cold/frozen and warm thaw cycle happens. The valve internally gets a small level of corrosion on the valve seat and it will allow a fine leak. All I can do is replace the valve and move on.

The Atwood water heater has the issue worse I think as the valve is closer to outside for corrosion. See here,

The gas valve out on the bench test. When they look like this, odds are high they will fail the LP leak test.
[image]

After cleaning up the heater and the outside of the gas valve, I do the LP test.
[image]

Yes, it leaks, the bubble test shows the location after the gage test fails.
[image]

New valve next to old, replace, retest, and all works well and passes.
[image]

New valve installed and under use testing
[image]

[image]

The Atwood stove, since it is inside the camper, the burner knobs I have not had much issue with. But the stove regulator, I can have a diaphragm leak. This leak was on a newer camper, only about 2 - 3 years old at the time. I'll leave the new Dometic non working stove regulator issue for another time.
[image]

[image]

The Domectic fridge, it uses a different type of gas valve. So far I have not had the fridge gas valves fail the leak test, even when 20 years old. I'm sure they can, but they do not seem to be as pronounced as the water heater being the worst, then the furnace.

Cleaned up mounting bracket on the old gas valve.
[image]

Leak check
[image]

Live test
[image]

When the camper is all back together, I do a total system LP test. This checks for anything in the system for leaks and tests the main tank regulator.

I do these 3 tests.

1. System pressure drop test. I hook up the gauge at a stove burner as it is easier to get into the system. You charge the system, shut off both LP tanks, bleed the pressure down to 8" WC to open the main tank regulator and then wait and look for a pressure drop. The time length may change by state etc. For sure nothing less then 3 minutes and no drop at all. I test longer into the 15 minute time period. After doing the bench tests, I normally have no issue passing 15 minutes. But, the main tank regulator and the hoses are always suspect. If the hoses are hard as a rock, I change them before I start. I have had many main tank regulators be bad, for regulation more then diaphragm Leaks.

2. Main regulator pressure set point test. Next if I have no leaks, I do the main system pressure setpoint. Here I need to get upstream of the stove regulator. Since I was on the gas burner control I have the down stream stove regulator pressure already, but I do not totally know the main system pressure. If I can get my 11" WC on the main pressure, I'm good to the next test. This can be where I start finding main tank regulators be bad. I adjust the main tank regulator as needed to get up to or down to 11" WC.

3. Main regulator lock up or max pressure test. This test point is still at the stove upstream of the stove regulator, but it tests the max pressure when the furnace and water heater are in operation. You do not want above 14" WC or a lot below 11"WC. This is where an old or sometimes new, tank regulators fails the test. A 20 year old RV style tank regulator is often a problem. Not always, but often. The system will not maintain stable enough not not go above or below the limits. Trying to adjust the setpoint is all you can do. So you replace the main tank regulator and start over on the leak checks and go again through the test.

The tanks hose fittings, either on the high side or the low pressure side have been a leaks source at the fittings. The main LP gas line sch 40 black iron pipe joints normally come out OK. The 3/8" copper hook up tubes to the appliance, if they are loose, they can leak. Leak bubble solution finds them.

The end results of my learnings are, RV grade LP gas components are not high quality like in a home or industry. Everything is throw away and not the greatest quality even when new. It's sad. I also see new campers being built now with flex rubber lines in place of older hard lines. I'm not sure I really like that idea. They are faster to install, but longevity the jury is out, along with the oil in the hose issues that can come from rubber lines.

Hope this helps

John


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JimK-NY

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Posted: 10/16/22 03:23pm Link  |  Quote  |  Print  |  Notify Moderator

John, thanks for the impressive detailed information. I know for sure I would like to avoid tackling all of these possible issues. At this point I am trying to assess the amount of leakage. I weighed my primary tank and have had it opened for 10 days. In another couple of weeks, I will do a weight check. I did check the HW heater again and think there is a very, very faint odor. So if I decide to do more checking and possible repairs, I will start there.

Thanks again.

3 tons

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Posted: 10/16/22 03:57pm Link  |  Quote  |  Print  |  Notify Moderator

Grit dog wrote:

3 tons wrote:

My camper has been sitting for about a month with the propane bottle shut off. After each use, I first shut off the appliances before shutting off the tank valve, because the camper rest in our RV garage…FWIW, after all this time I just checked and the regulator valve is still showing green…

The one thing that I can say is that teflon tape is not intended for use on any of the threaded brass fittings having tapered-ends…

3 tons


You included an extra word when you said “not” in the last sentence.
Hopefully no one follows those directions and just tries to crank pipe thread fittings together without tape or pipe dope….


Wrong, the operative word I used is ‘tapered’ (meaning a compression fitting)…With this type fitting no teflon or pipe dope is used because it might interfere with the compression seal, thereby resulting in a leak…Compression is what does the sealing-in of the gas (and why their use for gases…), threads are not what does the sealing…

For an example check this out at about 13 min in:

https://www.youtube.com/watch?v=oBRMRAZykJs

3 tons

JBarca

Radnor, Ohio, USA

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Posted: 10/16/22 06:04pm Link  |  Quote  |  Print  |  Notify Moderator

JimK-NY wrote:

John, thanks for the impressive detailed information. I know for sure I would like to avoid tackling all of these possible issues. At this point I am trying to assess the amount of leakage. I weighed my primary tank and have had it opened for 10 days. In another couple of weeks, I will do a weight check. I did check the HW heater again and think there is a very, very faint odor. So if I decide to do more checking and possible repairs, I will start there.

Thanks again.


Hi Jim,

Thanks for the good words.

What are your thoughts on what you will do with your 10 day weight loss test when you find the number? What will you declare as good or bad? As I said above, anytime I check an older camper LP system, odds are high something has a fine leak or leaks that can fail the standard pressure drop test. Once you know, you sort of have to go hunting and find it and correct it.

I agree, the water heater gas valve is suspect, you can move the gas burner tube off the end of the valve, charge the system with gas, and use leak solution on the brass tip of the valve. If it blows bubbles, it leaks. Odds are favorable, yours will have some level of leak.

Here is a post of mine from March of 2006 when I started into chasing camper LP leaks. It also shows capping off appliances to hunt down what is causing what leak or leaks. There is some good info there and some real good responses from other posters which may help you. https://www.rv.net/forum/index.cfm/fusea........d/tid/17306270/srt/pa/pging/1/page/1.cfm

An interesting one is by Chris Bryant almost all the way down the second page where he posted that about leak rate on the water heater valve. See here for a direct link to it. http://www.rv.net/forum/index.cfm/fuseac........d/17306270/gotomsg/17334969.cfm#17334969

Hope this helps and let us know how you come out on this.

John

JimK-NY

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Posted: 10/16/22 06:56pm Link  |  Quote  |  Print  |  Notify Moderator

It seems beyond doubt that there are some slow leaks. I just don't know the significance. Currently it takes about 6 hours for the pressure in the system to drop enough that the pressure goes below 5"water and the indicator switches to red. That seems like a small amount but I don't know. I have already passed the 10 day period and will wait about a month before weighing the tank. I only have a bathroom scale and need to see a drop of a pound or more. If a lose a pound every month or so, I will probably live with it. I have not seen any bubbles with leak tests and odor is absent or minimal.

I have not used my RV in over a year and barely used it since Covid started. After my month long test I plan to cycle the furnace, stove, HW heater and check afterwards using the switch over indicator.

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Posted: 10/16/22 07:46pm Link  |  Quote  |  Print  |  Notify Moderator

3 tons wrote:

Grit dog wrote:

3 tons wrote:

My camper has been sitting for about a month with the propane bottle shut off. After each use, I first shut off the appliances before shutting off the tank valve, because the camper rest in our RV garage…FWIW, after all this time I just checked and the regulator valve is still showing green…

The one thing that I can say is that teflon tape is not intended for use on any of the threaded brass fittings having tapered-ends…

3 tons


You included an extra word when you said “not” in the last sentence.
Hopefully no one follows those directions and just tries to crank pipe thread fittings together without tape or pipe dope….


Wrong, the operative word I used is ‘tapered’ (meaning a compression fitting)…With this type fitting no teflon or pipe dope is used because it might interfere with the compression seal, thereby resulting in a leak…Compression is what does the sealing-in of the gas (and why their use for gases…), threads are not what does the sealing…

For an example check this out at about 13 min in:

https://www.youtube.com/watch?v=oBRMRAZykJs

3 tons

Ummm, NPT threads are tapered and definitely need PTFE tape or pipe dope. You are confusing tapered (e.g. NPT threads) and compression fittings. Those are definitely not the same. As a matter of fact, while folks think NPT means National Pipe Thread, it does not. It actually means National Pipe Tapered.

CPC website


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Grit dog

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Posted: 10/16/22 09:41pm Link  |  Quote  |  Print  |  Notify Moderator

3 tons wrote:

Grit dog wrote:

3 tons wrote:

My camper has been sitting for about a month with the propane bottle shut off. After each use, I first shut off the appliances before shutting off the tank valve, because the camper rest in our RV garage…FWIW, after all this time I just checked and the regulator valve is still showing green…

The one thing that I can say is that teflon tape is not intended for use on any of the threaded brass fittings having tapered-ends…

3 tons


You included an extra word when you said “not” in the last sentence.
Hopefully no one follows those directions and just tries to crank pipe thread fittings together without tape or pipe dope….


Wrong, the operative word I used is ‘tapered’ (meaning a compression fitting)…With this type fitting no teflon or pipe dope is used because it might interfere with the compression seal, thereby resulting in a leak…Compression is what does the sealing-in of the gas (and why their use for gases…), threads are not what does the sealing…

For an example check this out at about 13 min in:

https://www.youtube.com/watch?v=oBRMRAZykJs

3 tons

10-4.
Flare or compression fittings. Yup.
I read as tapered threads.
Apologies.


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JBarca

Radnor, Ohio, USA

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Posted: 10/16/22 10:15pm Link  |  Quote  |  Print  |  Notify Moderator

I am going to mention something to maybe help diffuse something before it gets taken out of context, again.

Sometimes it is better to ask for clarification, then throwing darts in words.

I have been building machines for 40 years, in both the machine tool and food industries. Each industry has different slang and names for things that are used every day in their respective industry.

When brass machined fittings are called out, the ends of the fitting can have several names used by tradesmen.

NPT in the US I think we can all agree on, has tapered threads on pipe and fittings that require a thread sealant when making a pressure seal.

We also have other fittings that have tapered ends on them that are made out of brass, steel, plastic and other materials. The tapered ends are part of a compression seal setup that does "not" require sealant in the joint. The pipe or tube used to join with the tapered end fitting, has a flared taper on it to match the fitting and create a pressure tight seal without sealant.

Now to common brass fittings used in LP gas systems used in campers. There are a variety of them, some are all NPT tapered thread on all ends, while others can have only tapered flare ends or a combination of both. Here is where the joint naming can be miss read as the word taper shows up in both cases and may means something different pending ones background.

To me, a brass adapter fitting with a tapered end on it, I call it a flare fitting, not a tapered end fitting as that is from my background and industry I worked in. Other industries may call them out differently.

If any one has heard of Parker, they are one of the big fitting manufactures I used that they refer to them as flared fittings also. Again in the industry I have worked in. Other industries may call them something else.

There is 37 degree flare style made from steel for high pressure, https://ph.parker.com/us/en/37-flare-fittings

And there is 45 degree flare for lower pressure and the LP gas fittings we find in our campers. https://ph.parker.com/us/en/45-flare-fittings

A brass adapter fitting could have NPT tapered thread on one end and a 45 degree flared male or female connection on the other end. You use thread sealant on the NPT end and no sealant on the flared end.

While a flared fitting has a taper on the end, in the industries I come from, the taper word is not used in the call out, we use the word flare or flared end.

Hope this helps

John

JimK-NY

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Posted: 10/17/22 05:35am Link  |  Quote  |  Print  |  Notify Moderator

I don't mind electrical or most mechanical work, but I absolutely hate plumbing. Even replacing toilet parts is a task I hate. Even the shutoff valves never seem to work and always leak afterwards. Anyway, my knowledge of plumbing parts, valves, fittings, etc is poor. First time I had an old stiff and leaking pigtail, I tightened the Acme fitting until it cracked. It seemed like a really poor design, so I used lots of teflon tape on the replacement. Of course, I also used plenty of teflon on the 1/4" inverted male fitting. I was lucky I didn't have a leak. Fortunately I also learned better. Otherwise I would have been using a foot of teflon tape every time I changed the tank.

3 tons

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Posted: 10/17/22 06:57am Link  |  Quote  |  Print  |  Notify Moderator

Grit dog wrote:

3 tons wrote:

Grit dog wrote:

3 tons wrote:

My camper has been sitting for about a month with the propane bottle shut off. After each use, I first shut off the appliances before shutting off the tank valve, because the camper rest in our RV garage…FWIW, after all this time I just checked and the regulator valve is still showing green…

The one thing that I can say is that teflon tape is not intended for use on any of the threaded brass fittings having tapered-ends…

3 tons


You included an extra word when you said “not” in the last sentence.
Hopefully no one follows those directions and just tries to crank pipe thread fittings together without tape or pipe dope….


Wrong, the operative word I used is ‘tapered’ (meaning a compression fitting)…With this type fitting no teflon or pipe dope is used because it might interfere with the compression seal, thereby resulting in a leak…Compression is what does the sealing-in of the gas (and why their use for gases…), threads are not what does the sealing…

For an example check this out at about 13 min in:

https://www.youtube.com/watch?v=oBRMRAZykJs

3 tons

10-4.
Flare or compression fittings. Yup.
I read as tapered threads.
Apologies.


No apologies needed, lots of understandable confusion about this, additional clarity is warranted.

3 tons

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