How to Hook Up an External Propane Tank to an RV

Owning or renting an RV gives you some pretty good opportunities to do DIY tasks. These tasks may seem like a good way to play around or interact with your RV, but the reality is, that some of them are quite crucial to make use of your rig to the fullest. For instance, the heating and cooking system relies on propane that is fed through the propane container tucked beneath the floor. Running low on propane can, therefore can cause anxiety, especially in the winter when your very survival rests on this gas.

Fortunately, there is a way you can back up your RV’s compact propane tank and ensure that you don’t freeze in the bitter chill of winter. The solution is to attach an external propane tank to your RV which will supplement your existing tank quite adequately. Guaranteeing this additional source of propane also means you get to cook whatever you want whenever you need it.

However, hooking up an external propane tank to an RV isn’t as simple as turning off and on a knob or a switch. It requires some equipment and tweaks in order to work properly. Worry not, as the entire procedure is relatively straightforward and doesn’t require fancy equipment and advanced know-how.

Equipment Required

  • The first and foremost equipment you will need would of course be an external propane tank. In case you don’t have the budget or the long-term need to buy a whole new tank, you can rent one from a propane distributor or an RV park.
  • The second piece of equipment would be the pressure regulator. The regulator, as its name suggests, tones down/regulates the gas pressure to a safe limit before it reaches your appliances. The gas in the tank is highly pressurized (100-200 PSI) and connecting it without a regulator would lead to disastrous consequences. RV appliances are generally rated at 0.4 PSI, so a pressure regulator is an absolute necessity.
  • External propane tank adaptor – It is also known by many other names such as Extend-a-stay-kit, Extend-a-stay-adaptor, Stay-a-while, and Stay-a-while-deluxe. This adaptor allows you to attach your RV propane system to an external propane tank which then acts as a secondary gas supply to the tank. The adaptor contains caps to prevent accidental leakage of gas from unused ports and the unused ports themselves can be used to hook up any additional propane-powered appliance (e.g., grill, heater, etc.).
  • Generally, the above-mentioned kits come with a hose, however, if yours doesn’t come with one then it is good to buy a hose or two as they usually come in handy if your existing hose develops a leakage or if your external tank is located far-off and it isn’t mobile.
  • Soapy water solution in a sprayer bottle or a gas leak detector – this will allow you to detect leakage. These solutions bubble up upon contact with gas which immediately lets you know of a leakage. Gas leakages are often quite hard to pinpoint from the naked eye which is why keeping one of these solutions always helps when working on a propane or methane gas-related task.
  • Yellow thread tape – this tape is particularly made for use on gas connections to avoid leakage.

A Word of Advice

Before we move on to describe the process of hooking up an external propane tank to an RV, it is important that we first address an important issue. There’s a good chance that this issue won’t be anywhere in your distant expectations, but you can stumble upon it if you lie in the minority of RVers. The following paragraphs discuss it in detail:

In the majority of the cases, you can connect one end of the hose directly to an external propane tank and the other one to an extend-a-stay adaptor that is already hooked to a pressure regulator on the RV. However, there is a catch if your external tank is located far off and the weather outside is chilly. The regulator installed on the external tank located far off will, in combination with the regulator of the onboard tank won’t be able to push gas at high enough pressure for any appliance to work. This is because the extend-a-stay installed right beside the built-in propane tank of an RV is on the upstream side of an RV’s original regulator. The OEM regulator together with the external tank’s regulator will reduce the gas’s pressure to such an extent that it won’t even light up your stove or any other appliance.

In such a case, you don’t need to eliminate the external tank’s regulator altogether. Eliminating the regulator from an external tank located at a long distance in cold weather would lead to the formation of oil inside the hose. Consequently, this would gum up the regulator on your RV’s onboard propane tank. To avoid this, it is advised to use a different regulator for the external tank, a regulator that doesn’t reduce the pressure to 0.4 PSI but tones it down to 10 PSI so the gas can flow freely in winter without causing oil formation in the hose and at the same time can light up the appliances. The 10 PSI regulator in conjunction with the onboard regulator would work like a charm for all your gas-run appliances.

Now that we have described this in detail, it is time we discuss the process of connecting an external propane tank to your RV:


Shut off the Propane and Disconnect the Regulator

Just like we shut off the water supply when working on the plumbing system, the propane system also needs to be turned off before making any changes. The knob on top of the cylinder serves this very purpose and all you have to do is to turn it in a close direction. Once the supply is off, disconnect the regulator from the propane tank as well.


Connecting the Extend-a-Stay kit

Once done with the prerequisites mentioned above, install the extend-a-stay kit to your RV’s onboard propane tank. The adaptor will act as a bridge between your RV’s onboard tank and the regulator. Use the yellow tape to ensure a leak-free connection.


Installing the Regulator

The regulator needs to be installed on the propane tank. It will reduce the extremely high pressure of the gas in the tank and then deliver the gas to your RV. Whilst making connections, ensure that every potential point of leakage is taped and firmly connected so no adjustments are needed after the supply is turned on.


Attaching the External Propane Tank

The next task is to connect your external tank with the hose that is connected to port D of the adaptor. Hopefully, your hose is long enough to reach the tank safely, if not, then you will need to buy a longer one.  

As explained earlier, there is no need to attach a pressure regulator to the external tank as the gas from the external tank will be flowing through the regulator attached near the onboard tank. Though, if the tank is located far away and the weather is chilly then you will need to go through the process described in the “a word of advice” section.


Leak-proofing the Setup

Now that all the connections have been connected, it’s time to turn on the gas and look for leaks. This is where the soapy water solution comes in handy. Spray it richly one by one over all the connections and inspect closely for the formation of bubbles. If you detect bubbles anywhere, then immediately turn off the gas supply and rectify the issue.


Yes, you can certainly connect any external gas appliance to your RV. To do so attach the appliance to a t-fitting or a quick disconnect on the extend-a-stay kit.

Yes, two tanks can be connected, however, you will an auto changeover feature to make them work.

No, you cannot use the extend-a-stay kit to refill the RV propane tank. The kit can only be used to connect an external source of gas.

The laws vary from state to state, though the majority of the states allow driving with some propane appliance running in the background. However, for your own safety, it is not advisable. Running such appliances while driving raises the risk of fires especially if the RV met with an accident.

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Ever since I was a kid, I've been fascinated by travel. I inherited this passion from my parents. Since my college years and to this day, I have had a passion for traveling in a motorhome. I am here to share my experiences with you.

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