Propane tank valves are closed and I can run all propane applainces

[taylor.coyote]

Any wisdom on how this is possible? Tanks standing alone (not attached to the trailer) with valves closed do not leak. 

 

[FloraFauna]

Residual gas in the appliances and the lines?  Can't imagine it would last long once the pressure is relieved, but the appliances are pretty good at sipping propane.  

[taylor.coyote]

Possible answer. I'll give it more time to see if the flame on the stove top dies

[jd1923]

On 10/11/2025 at 12:43 AM, taylor.coyote said:

Any wisdom on how this is possible?

Residual gas in the trailer LP plumbing would NOT be enough to start a flame on the stovetop at all, or if it did so it would burn out in seconds.

I believe one/or both of your tank valves is/are either open or bad. If you can truly run the cooktop for any length of time, the tank valve is OPEN. We always run gas through the cooktop for a few seconds (lit or not) before turning the fridge to LP, turning on the HWH, or furnace, to bleed the lines with pure gas up to that point.

However, for gas to flow from an LP tank, both the internal valve has to be open and the LP line with the correct connector needs to be attached. Both the valve open AND the line connected is necessary for LP gas to be released from the tank (redundancy for safety).

Either it's something as simple as your tanks valve(s) are NOT closed (righty-tighty), or you valve is bad, failed in an open position and it's not apparent until the line is connected that the valve is actually open. Hope this helps!

This Q&A on this website explains:
https://www.propane101.com/valveopennopropane.htm

[Steph and Dud B]

Just to be sure: clockwise to close.

[SeaDawg]

Right tighty, lefty loosey.

You'll get some little bit of  gas when everything is closed, but just a tiny bit.

If you get more than a bit, you have a faulty valve, or didn't actually close it.

[taylor.coyote]

Thanks for all the feedback.  Got it, righty tight / lefty loosey.  No mistakes with open valves. Discounted  both tanks from trailer, tank valves closed no leaks..  lit stove top and burned off all propane left in the line until flame died.  Hooked up propane tanks with valves remaining closed. Was able to lite stove top with  modest pressure driving the flame. Able to burn modest flame on stove top as long as stove top valve is open. 

Clearly we have a leak in one or both valves when hoses are connected. Seems at least one a bad valve. The part I don't understand: why I'm not able to detect a leak when the tanks are disconnected.  Do the hose interface pins  release a gate in the tank valve? 

 

Edited October 13 by taylor.coyote
typo

[Steph and Dud B]

9 hours ago, taylor.coyote said:

Do the hose interface pins  release a gate in the tank valve? 

Yes, exactly.

[Geronimo John]

2016 Legacy Elite II, Twin Beds, Hull #124

It's likely time for you to replace both tanks anyway.  If the propane pressure regulator is OEM, I would replace it as well!

GJ

[Dennis and Melissa]

On 10/13/2025 at 11:09 AM, Steph and Dud B said:

Yes, exactly.

Even when the tank is closed?  How is that possible?  It completely negates the whole idea of closing a tank!

[Steph and Dud B]

4 minutes ago, Dennis and Melissa said:

Even when the tank is closed?  How is that possible?  It completely negates the whole idea of closing a tank!

See what the OP said:

On 10/13/2025 at 1:57 AM, taylor.coyote said:

Clearly we have a leak in one or both valves when hoses are connected. Seems at least one a bad valve.

There are 2 things that stop propane from exiting the tank, first the manual valve, then the pin actuated gate. If the manual valve is open - or faulty - connecting the tank to a propane line will allow gas to flow. That's what appears to be happening here.

 

[Rivernerd]

Time to replace both tanks, and as Geronomo John recommends, the regulator as well.

[taylor.coyote]

Yep, new tanks are on order....

 

thanks to all

[jd1923]

On 10/29/2025 at 2:45 PM, Geronimo John said:

If the propane pressure regulator is OEM, I would replace it as well! GJ

On 10/31/2025 at 9:01 AM, Rivernerd said:

Time to replace both tanks, and as Geronimo John recommends, the regulator as well.

Our Oliver is my first experience with the dual LP regulator setup. Previous RVs had single built-in tanks. Is this necessary merely due to age?

Our hull now approaching 10-years-old with OEM regulator. I haven't used the auto change-over feature, just turn the valve left or right. Everything is working as designed.

This may be a good replacement, or is there a preferred brand?

https://www.amazon.com/RecPro-Regulator-Changeover-Connector-Mounting/dp/B0DK626918/ 

[topgun2]

17 minutes ago, jd1923 said:

Our Oliver is my first experience with the dual LP regulator setup. Previous RVs had single built-in tanks. Is this necessary merely due to age?

Our hull now approaching 10-years-old with OEM regulator. I haven't used the auto change-over feature, just turn the valve left or right. Everything is working as designed.

Our Ollies are very close in age.  I have never had any issues with any of the tanks and/or regulators on any RV I've ever owned and up until this year I too had a similar experience to yours.

However, for this year's 2 month fishing trip to Wyoming I noticed that I seemed to using a bunch more propane than I should.  This got me to looking at hoses that connected the tanks to the regulator.  Even though the hoses were only about two years old, one of them was leaking.  Fortunately, while I was in Dubois, WY there was a relatively new Ace Hardware store in town that had a new hose that would fit.  Great - problem solved!

Not so fast Bucko!  I was still using propane faster than I thought I should.  As with the story above, I broke out my propane sniffer that I happened to carry on this trip.  Bummer, the readings were not consistent, but, seemed to confirm that I still had a leak somewhere.  I even used my Gas-Stops to detect a leak and they confirmed a very slow leak.

Fortunately I was headed to Hohenwald for my annual visit and I asked Jason to have the guys take a look.  It took awhile, but, they finally confirmed that the regulator was leaking.  New regulator, new hoses and full tanks of propane make for a happy camper.

Bill

[Geronimo John]

JD:  I also do not use the auto change over valve.  For those of us who want to know when a tank has run dry, why not replace the change over valve with a "T".  Then replace the getting gray hair OEM hoses with less "tight turns" ones that the change over OEM setup has.

All:  Any unintended consequences that come to mind would be appreciated.  

PS:  I do think it wise to carry a spare regulator.  Would be interested in a good brand.  Below is what over the years I harvested from several owners:

GAS REGULATOR:

·       The OEM Hull 505:   GR-9984XF with 345,000 BTU from the Main Service Cylinder.

·       Possible Smaller Replacement Part if above is not available:  GR-9994XF has 262,500 BTU

 PROPANE REPLACEMENT HOSES:   12” with 90⁰ Street Elbow Preferred

 Topgun2 Cautions:  A couple of notes:  Check the size of the connections on the hoses.  Be careful that you do not over-tighten the fittings.  I believe that the torque setting is 25 foot pounds (confirm this).  Use yellow "gas" tape or gas pipe dope. 

 May need a ¼” male NPT X  ¼” Female inverted flare fitting.

[Ronbrink]

8 hours ago, Geronimo John said:

JD:  I also do not use the auto change over valve.  For those of us who want to know when a tank has run dry, why not replace the change over valve with a "T".  Then replace the getting gray hair OEM hoses with less "tight turns" ones that the change over OEM setup has.

All:  Any unintended consequences that come to mind would be appreciated.  

PS:  I do think it wise to carry a spare regulator.  Would be interested in a good brand.  Below is what over the years I harvested from several owners:

GAS REGULATOR:

·       The OEM Hull 505:   GR-9984XF with 345,000 BTU from the Main Service Cylinder.

·       Possible Smaller Replacement Part if above is not available:  GR-9994XF has 262,500 BTU

 PROPANE REPLACEMENT HOSES:   12” with 90⁰ Street Elbow Preferred

 Topgun2 Cautions:  A couple of notes:  Check the size of the connections on the hoses.  Be careful that you do not over-tighten the fittings.  I believe that the torque setting is 25 foot pounds (confirm this).  Use yellow "gas" tape or gas pipe dope. 

 May need a ¼” male NPT X  ¼” Female inverted flare fitting.

The auto changeover (dual) regulators do have issues and many choose not to rely on them and thus, would rather resort to turning only one tank on at a time. Adding a ‘T’ would suffice for the ‘one tank on at a time’ users, but would still require a (single) regulator. Regardless and to your point, carrying a spare could ‘save the day’ (think camping trip!) in the event of a regulator failure due to wear or a malfunction. Your mention to use a 90° street elbow is golden, better fitment with less bends in the hoses!

[Geronimo John]

16 hours ago, Ronbrink said:

Your mention to use a 90° street elbow is golden, better fitment with less bends in the hoses!

Two get backs:

A.  If I recall that was a DIY of the past.  Your pictures certainly demonstrate its usefullness for all owners to seriously consider.   Thanks for posting the pic. I do hope that OTT has picked upon the idea as it is a no brainer for them to just do.

B.  Your picture is also "Gollden" in another way!   Love the tank gauges!

GJ

Edited November 4 by Geronimo John

[topgun2]

9 hours ago, Geronimo John said:

Your picture is also "Gollden" in another way!   Love the tank gauges!

As you might already know - 

Those tank gauges are "GasStops".  They are primarily designed to automatically stop gas flowing in the event of a major "leak".  However, they can also be used to detect a slow or minor leak and they are a "gross" source of determining how much gas is left in the tank.

GasStops can be found at Camping World, Etrailer, and a bunch of other places to include HERE on Amazon.

Installation is very simple.

Bill

[Ronbrink]

22 hours ago, topgun2 said:

they can also be used to detect a slow or minor leak and they are a "gross" source of determining how much gas is left in the tank.

AND have a purge feature when first opening the tank valve. No more trips inside to check for gas flow at the cooktop!