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RV Propane Tanks 101: How to Refill RV Propane Tank

Updated: May 10

Learn all about RV propane tanks, types of RV propane tanks, carrying propane tank in an RV, refilling propane tanks, and more.

rv bike rack over propane tanks

RVs give you the chance to take your home with you on the road. Many different systems of your motorhome like the electrical system and plumbing lines work together to make this dream come true. Another essential component that helps make life on the road more comfortable is your RV propane tank. You may think that propane is only useful for running your RV stove, but it can do so much more than that.

From running your RV water heater and furnace to powering your refrigerator, propane can help run a lot of the amenities that make #riglife comfortable. Read on to learn more about your RV propane tanks, how they work, and how to refill them plus maintenance tips and tricks to help you get the most of your propane tanks.

What is RV Propane Tank and why is it Important?

Propane or liquified petroleum gas (LPG) or simply LP gas powers a lot of amenities in your RV. It is a colorless, nontoxic compound that is compressed and stored as a liquid in specially-designed tanks known as propane tanks. These propane tanks help you store and carry propane safely on your RV road trips. While you can power almost everything in your RV through shore power, propane tanks give you the freedom to boondock or camp off the grid by powering most of those amenities without the need for a power connection.

RV propane tanks can help power RV water heaters, stovetops, furnaces, refrigerators, BBq grills, and other smaller appliances easily. Make sure to check your motorhome manual to check which appliances and amenities can be run using propane gas.

Types of Propane Tanks in an RV

There are two basic types of propane tanks you will find in an RV. The type of RV propane tank you have depends on the type and size of your RV, your RV lifestyle, and your personal preference.

Built-in RV Propane Tanks: ASME Tanks

Most Class A motorhomes and larger RVs come with built-in RV propane tanks known as ASME tanks. They are named so because these propane tanks are certified by the American Society of Mechanical Engineers. ASME tanks are horizontal RV propane tanks that are installed underneath the cabin close to the main entryway in a motorhome. ASME tanks are installed as a single unit and are held in place by propane tank mounting brackets for RV.

40lb rv propane tank

The tanks range in length from 2-12 feet and in diameter from 10-30 inches. Since they come pre-installed in your RV all their connections are entirely secure. ASME tanks don't need to be recertified since they are professionally attached, secured, and protected. Most ASME tanks come with a propane tank gauge that tells you how much propane is left inside the tank. You can refill these tanks just like you refill your petrol tank.

ASME tanks are already installed in your motorhome so you don't have much choice when it comes to deciding the size of the tank you want (generally a larger motorhome will have a larger tank). However, if you do get the choice go for as big a tank as you can afford to really reap the benefits of this source of power.

Portable RV Propane Tanks: DOT Cylinders

Fifth-wheels, travel trailers and smaller campervans are usually powered by portable propane tanks called DOT cylinders. These cylinders are certified by the Department of Transportation (hence the name) and you can find them in most hardware stores and convenience shops easily. These portable cylinders are usually kept as a pair and are situated vertically on the tongue or back bumper of most smaller RVs.

rv propane tank lock

DOT cylinders are normally available as 20lb or 30lb cylinders that can carry roughly 5-7 gal of propane. While the 30lb cylinder carries more propane it is also difficult to source which is the reason why the 20lb DOT cylinder is used a lot more frequently by RVers. Regardless of what size propane cylinder you buy, DOT cylinders need to be refilled or exchanged as per your need.

Many RVers prefer keeping their own cylinders and re-filling them with propane as and when needed. Personal DOT cylinders need to be recertified once they're 12 years old and then every five years after that. You don't need to recertify exchanged cylinders.

RV Propane Tank Sizes

RV propane tank sizes vary depending on the type of RV you own, your propane needs, and the RV propane tank set-up in your rig. ASME tanks vary in size from 20 pounds to upwards of 420 pounds (carrying 100 gallons of propane!). DOT cylinders are available as 20lb or 30lb cylinders which gives you the freedom to carry as much or as little as you need. Let's say you want a 100lb RV propane tank setup for your travel trailer, you can easily do that by setting up five 20lb propane cylinders or going for a mix of 20lb and 30lb RV propane tank setup.

how to switch propane tanks on rv

Note: Always consult a professional before setting up or expanding your RV propane tank setup.

What Size Propane Tanks do I Need for my RV?

There are many factors that dictate the size of propane tanks you need for your RV including:

  • The size and type of your RV

  • The number and type of amenities you need to power through propane

  • Your total propane usage/requirement

  • The frequency of use for each appliance/amenity

You can use your tank’s and appliances' British Thermal Unit (BTU) capacity to figure out how much propane you will actually need to power your RV. You can find BTUs for each appliance in their user manual, generally:

  • Furnaces have a BTU of 20,000 and 40,000 depending on their size.

  • Cooking ranges use around 10,000 BTU an hour, when on.

  • Propane fridges use around 1,500 BTU per hour.

  • Grills use around 8,000 -10,000 BTU per hour depending on their size.

One pound of propane produces around 21,548 BTUs. However, your propane tanks should only be filled to 80% of their capacity to give the gas room to expand. This means that a 30lb propane tank can carry 24lb of propane and can produce 517,152 BTUs (21,548 x 24)

So if in a typical day you run your:

  • RV furnace for 2 hours (30,000×2)

  • Cooking range for 1 hour (10,000×1),

  • Fridge for the whole day (1500×24)

That gives a demand of around 106,000 BTU per day. Now divide your total usage per day with the total capacity of your propane tank (517,152/106,000) and this tells you that your 30lb propane tank can power your amenities for up to 5 days.

How Long does an RV Propane Tank Last?

How long a propane tank will last depends entirely on how often you are using the appliances it powers. If you're boondocking in the wilderness and running your water heater, stove, and refrigerator frequently then you might need to refill your tanks within a few days. However, if you are a seasonal camper who likes to park at campgrounds with full amenities you might not need a propane tank refill for weeks.

Note: It is recommended to pack extra propane when hitting the road for your next RV adventure. You never know when you'll need that extra propane to run an appliance.

How to Fill RV Propane Tanks?

RV propane tanks need to be filled the same way your fuel tank does. The only difference is that you might not need to refill propane tanks as frequently (depending on your use). Most propane filling stations will re-fill your propane tanks for you, however, if you come across a self-serve station you can follow the steps outlined below to fill your propane tanks.

Note: Make sure you read your tank's manual carefully before refilling it yourself. Don't go in blind, do your research and consult a professional before RV propane tank refill, especially DOT cylinders.

Re-Filling ASME Tanks

  • Inspect the ASME tank for any leaks, cracks, shell damage, or deterioration. Make sure to rectify these before filling the tank.

  • Wear neoprene gloves to protect your hands from frostbite (liquid propane is extremely cold)

  • Open the intake valve on the tank.

  • Attach the RV propane hose to your tank.

  • Open the close-release valve on your tank and on the refill hose to start refilling propane.

  • Open the bleed valve on the tank to check if the tank is full. Once the valve releases some propane as steam your tank is full.

  • Double-check the RV propane tank gauge to make sure the tank is full.

  • Close the bleed and release valves on your tank and the refill hose.

  • Unscrew the refill hose and return it to its proper location.

Re-Filling DOT Cylinders

  • Check your cylinder/s for any signs of damage like dents, bulges, rust, etc. Rectify these before filling the tanks.

  • Make sure the cylinder/s has an overfill protection device installed. If the cylinder has a triangular handle with the letters 'OPD' stamped on it, then you're good to go. Otherwise, don't refill the tank yourself.

  • Don't fill expired DOT cylinders. Check the expiration date on top to make sure the cylinder is under the 12-year mark.

  • If the tank is good to go, check its capacity to make sure how much propane you need to fill.

  • Connect the cylinder to the source tank with a refill hose.

  • Open the valves on both the cylinder and the source tank to refill the propane.

  • Close both valves when the cylinder is full.

  • Use the bleed valve on the cylinder to release excess propane.

  • Remove the refill hose and replace it in its proper place.

Exchanging DOT Cylinders

You can also opt to exchange DOT cylinders instead of re-filling them. You can easily find RV propane tank replacements in different gas stations, supermarkets, and hardware stores. Simply walk in with your empty cylinder and exchange it for one that is full. This option is a little bit more expensive than refilling the tanks but it is safer and more convenient.

Where can I fill my RV Propane Tank?

Propane is pretty easy to source in the US so you don't have to worry about finding a place to fill RV propane tank. You can find propane at:

  • Propane filling stations

  • Supermarkets

  • Hardware stores

  • U-haul stores

  • Gas stations

  • RV dealerships

  • Vehicle repair centers

  • RV campgrounds and parks

While you can easily find propane on the way, it is always recommended to stock up, especially if you're headed on a long road trip or on a new route. If you're planning to camp at campgrounds make sure to call ahead and check if they provide propane refilling facilities.

RV Propane Tank Accessories

ASME tanks usually come with all necessary propane tank components pre-installed but you might need to buy some of them for DOT cylinders.

DOT cylinders need to be properly placed and secured so that they don't get damaged while traveling. RV propane tank mounts and holders are a great way to do just that. All you have to do is take your RV propane tank dimensions and install a holder that matches them. Then simply mount your tanks to the holder to keep them in place and you're good to go.

RV propane tank holder

Most ASME tanks come with a gauge already installed so you can see how much propane is left inside the tanks. Consider buying an RV propane tank fill valve adaptor and a portable propane tank gauge to keep track of the propane inside your DOT cylinders. This is a great way to make sure you never run out of propane on your trips.

RV propane tank gauge

DOT cylinders are usually mounted outside your travel trailer or camper which means they need to be protected from the elements. Invest in good RV propane tank covers to keep your tanks safe and secured. You can also buy a reinforced RV propane tank cover lid when you're traveling to places with extreme weather.

Rv propane tank cover

An RV propane tank regulator helps manage the pressure and amount of propane that travels from the tanks to your appliances. This is a must-have accessory as it helps you meter your propane use and protects both your tanks and your appliances from damage.

rv propane tank regulator

Cost of Propane

The cost of refilling propane in your RV propane tanks varies from $2.00 to $2.75 per gallon in the US. Buying a new propane tank can cost $5 to $3,500 for sizes between 1 to 1,000 gallons (with additional installation costs of $275 to $5,150). A 15-30-pound propane tank or cylinder that you can exchange at the store starts at $30 and goes up depending on the size. Exchanging an empty cylinder for a full one can cost you anywhere from $10 to $25.

Once a DOT cylinder reaches an expiration date (12 years for a 20 or 30lb cylinder) you must request an inspection before you can refill it. Recertifying a propane tank costs around $35 to $60 depending on where you're getting it recertified.

RV Propane Tank Maintenance Checklist

Here is a simple checklist to help you maintain your RV propane tanks easily and hassle-free.

RV propane tank maintenance tips

The Last Word

Propane helps run a lot of different systems and appliances in your RV. It is cheap, safe to use, and can be easily sourced. However, you need to learn all about your RV propane tanks and how they work before you can start using propane efficiently. Always consult a professional when deciding to upgrade your RV propane tank system or before refilling your propane tanks for the first time.


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