Propane question

I just had a 120 gallon propane tank delivered. Unfortunately they didn’t notify me when they were coming and hooked it up and left. I opened the valve and thought I was good to go. Well I came home tonight and my small tank on the other side of the trailer must of ran out of propane and it didn’t switch to the the new one. Well needless to say at 2am when I got home it was 34 degrees outside and 40 inside my 5th wheel. I plugged in my portable heater and bundled up for the night. Help! What am I doing wrong? I shut off the small tank and still nothing. I am new to this full time RV living and going a little bonkers! I have a 2007 Thor Jazz 5th wheel

Thanks!

KMLsquared wrote:
Has anyone had a auto changeover regulator fail and allow propane to escape when a cylinder is removed for filling? I had a strong gas smell and my heater would not fire while trying to use one tank with the other tank disconnected.

I will suggest to replace the pig-tails along with the regulator.
I have and recommend Cavagna brand for both.

KMLsquared wrote:
Has anyone had a auto changeover regulator fail and allow propane to escape when a cylinder is removed for filling? I had a strong gas smell and my heater would not fire while trying to use one tank with the other tank disconnected.

my setup has a check valve where the hose from each tank attaches to the regulator.

And as Chris said, I have seen where it will draw from both tanks under high demand and cold temps.

Has anyone had a auto changeover regulator fail and allow propane to escape when a cylinder is removed for filling? I had a strong gas smell and my heater would not fire while trying to use one tank with the other tank disconnected.

TXiceman wrote:
At 0 degF it has a pressure of 24 psig, which is well above the 11 in of water column that is required to operate the appliances in an RV.

That needs to be the propane temperature... not the outdoor temperature.

As the propane boils off inside the cylinder there is a cooling effect and heat needs to be absorbed from the outside. With low volume this heat transfer slows down (see diagram posted earlier). I believe it would be easy for the liquid propane to be 10 to 20+ degrees below ambient during heavy usage and low in the cylinder.

TXiceman wrote:
Chris, Propane, AKA R-290. at zero pressure is -43.7 degF. At 0 degF it has a pressure of 24 psig, which is well above the 11 in of water column that is required to operate the appliances in an RV.

But the unit switches tanks at ~20 psi, thus drawing from both cylinders

If you get so low, that the boil off is this critical, you can always put a 100 Watt light bulb in the compartment with the tanks.

Exactly what we do- most people will not RV in below zero weather, those who do are aware of this problem, those who are not aware find both cylinders empty.
FWIW, we went through a 40 lb cylinder in a day and a half. On the road I; Wisconsin in December gets chilly.

Chris, Propane, AKA R-290. at zero pressure is -43.7 degF. At 0 degF it has a pressure of 24 psig, which is well above the 11 in of water column that is required to operate the appliances in an RV. See chart at
http://virtualmark.net/wx/pressure.htmhttp://virtualmark.net/wx/pressure.htm

If you get so low, that the boil off is this critical, you can always put a 100 Watt light bulb in the compartment with the tanks.

Ken

TXiceman wrote:

Chris Bryant wrote:
One caveat- the changeover works on pressure, if it is very cold, the regulator will draw from both cylinders.

And just how does this work? Never saw this in 35 year of RVing.

Ken

At zero degrees, a half full 30 lb cylinder will not supply a 35 k btu furnace, as it cannot absorb enough heat from the surroundin* air.

I used two clothes pins, one painted green, one painted red. It worked :)

Here is a pic of the gadget/propane level checker I mentioned earlier.



Jerry