Extend-a-Stay question

Thanks for all the responses. I was just doing this so if the small tank ran out in the middle of the night, I wouldn't have to get up and do a changeover. Everything worked great and I kept warm until the a. m.

Electric heaters upstairs won’t keep the wet and tank bays warm.

We don't use both at the same time. We do as Mr. Wizard and use the big tank only as backup or emergency, refilling the small tank when it's empty.

As far as an electric heater, that depends on the cost of electricity. Here in Yuma it is cheaper to use propane than it is to use the electricity, and there are other areas around here that the cost of electric is even higher.

Dale.Traveling wrote:
Don't see a problem but the big question,except which tank will be consumed first? Main, portable or will both run out at the same time?

It is impossible (with both tanks open) to tell which one is supplying gas till they run out.. So long as either tannk has gas in it you will have full pressure both sides of the regulator. pressure is NOT dependent on how much gas is in the tank, any amount, even a couple of ounces of liquid will give you full tank pressure.

So close one tank (The AUX would be my suggestion) till the main runs dry or close the main and when the aux runs dry haul ti to the refiller and run on main.

If it's cold, you will draw down the horizontal tank more, because it will vaporize more than a vertical.

If you're using it for heat, why not get an electric space heater like one of the ceramic heaters or one of the amish-types that will keep the rig warm without using a lot of propane? Unless you're boondocking, that is..... ;-)

MrWizard wrote:
vacation or extended stay ?

I would Not do it

if both are full, you are going to run low on both
if one is half and one is full, the higher pressure full one is going to bleed over to the other one until they are equal
then consume both at the same time, yes it will last longer

you run the risk of running out and having nothing at all

if the portable runs out you can turn it off and open the frame tank

keep to {2} portable cylinders,
connect one, when its low, change it
less likely to run out that way

Well, actually, in a vapor withdrawal system, the vapor pressure is going to be the same even if one tank is empty, then only vapor will transfer. No liquid propane will transfer between tanks. As long as either tank has a tablespoon of liquid propane in it, the vapor pressure will remain constant in both tanks. When the last of the liquid boils off, the pressure will drop rapidly. That is why the line pressure gauges are, for all practical purposes, useless. When the pressure drops, you are out of propane!

Tinstar wrote:
X2 what MrWizard said.

same same here

JimR

If I'm going to sit in one spot for a few weeks, I fill the frame tank just before I park it. I then treat this as back-up and emergency fuel. I install the extend-a-stay hose, and a 30LB cylinder. If it runs out in the middle of the night, I switch valves and run the on-board tank until morning, when I can refill the 30. At no point are both valves open at once, and I avoid using the frame tank as much as possible. At the end of a couple months long stay, the on-board tank still has quite a bit of propane. MrWizard probably does it better than me, by having two spare tanks, but I really don't have the room for any more tanks, so one works fine.

X2 what MrWizard said.