Why not have a second tank?  Then if the first one is empty use the second and refill the first. 
That&#x27;s pretty much guaranteed not to fail, unless you have someone that doesn&#x27;t fill the tank.  But that&#x27;s s different problem.
That&#x27;s what I do at home and it is only for the occasional grilling, not anything like &quot;we can&#x27;t eat &#x2F; have heat unless this works&quot;