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.