Buying a propane tank for your RV sounds like it should be the simplest purchase in camping. Then you start looking, and you run headlong into a wall of jargon: DOT versus ASME, pounds versus gallons, Type 1 valves, recertification dates, horizontal versus vertical. Suddenly, the simplest part of your rig feels like the most confusing.
I have spent more than two decades helping RVers sort through exactly this, and the good news is that once you understand a few core ideas, choosing the right tank becomes genuinely straightforward. There is no mystery to it, only a handful of decisions that depend on what kind of RV you have and how you camp.
This guide walks you through those decisions in plain language: the two fundamental tank types and which one your rig uses, how to think about size without over- or under-buying, the valve and recertification rules that keep you legal at the fill station, and the mounting realities you need to plan around. By the end, you will know exactly what to look for.
Let us take the confusion out of propane and get you to the right tank with confidence.
This is the single most important distinction, and everything else flows from it. RV propane comes in two fundamentally different forms, and which one you need is determined by your RV, not your preference.
DOT cylinders are the removable bottles you see standing upright on the tongue of travel trailers and fifth wheels. You can lift them off, carry them to a fill station or exchange, and swap them yourself. They are regulated by the Department of Transportation, which is where the name comes from, and they are the most common type in the RV world by a wide margin.
ASME tanks are permanently mounted to the RV's frame, almost always on motorhomes. They do not come off; you fill them in place at a station that comes to the tank rather than the other way around. They are built to a different standard, typically hold more fuel, and are not subject to the same recertification clock that governs DOT cylinders.
So the first question answers itself by looking at your rig. Trailer or fifth wheel with bottles you can lift off? You are in DOT cylinder territory. Motorhome with a tank bolted to the chassis? That is an ASME tank. Knowing which camp you are in narrows every other decision that follows.
One more practical note on telling them apart: if you are ever unsure which type you have, look at how the tank is attached and how it gets filled. If you can release a clamp or wingnut and lift the bottle off to carry it somewhere, it is a DOT cylinder. If filling means a truck or station servicing the tank where it sits, bolted to the frame, it is an ASME tank. That physical test settles it instantly, and it determines everything from recertification rules to how you shop for a replacement.
Once you know your type, size is the next decision, and the honest guidance here is to match the tank to how you actually camp rather than buying the biggest or smallest option on reflex. Propane capacity is usually expressed in pounds for DOT cylinders and gallons for ASME tanks.
For most travel trailers, the 20 lb and 30 lb cylinders are the workhorses. They balance a meaningful fuel reserve against a weight you can still lift onto the tongue, and they fit the tank racks most trailers come with from the factory. If you run your furnace hard in cold weather, lean toward the larger size so you are not chasing refills mid-trip.
It also helps to think in terms of runtime rather than abstract pounds. A rough rule many RVers use: a 20 lb cylinder runs a typical furnace for a long weekend in mild weather, far less in deep cold when the furnace cycles constantly. If you camp in shoulder seasons or boondock without hookups, that real-world math usually argues for more capacity than you would first guess, which is why so many cold-weather campers step up a size.
The Flame King YSN301 30 lb cylinder is the size I point cold-weather and longer-trip campers toward. The extra ten pounds over a standard 20-pounder translates into noticeably more furnace and appliance runtime between fills, which matters most exactly when refilling is least convenient, the cold shoulder seasons when you are running heat overnight.
It ships with a Type 1 overflow protection valve, the current standard we will cover in a moment, so it fills cleanly at any modern station. For trailers whose racks accommodate the 30 lb size, this is the sensible balance of capacity and manageable weight.
Buy Flame King YSN301 30 lb Propane Cylinder
At the other end, the King Flame 10 lb tank suits pop-ups, teardrops, truck campers, and anyone who would rather lift a lighter bottle more often than wrestle a heavy one. It carries a real fuel reserve while staying genuinely easy to handle, and it also makes an excellent dedicated tank for a grill or fire pit, so your main cylinders stay reserved for the rig.
It also carries the Type 1 valve. The trade-off is simple and predictable: less fuel means more frequent fills, so choose this size when manageable weight and compact storage matter more to you than maximum time between refills.
Buy King Flame 10 lb RV Propane Tank
Motorhome owners play by different rules. Your propane lives in a permanently mounted ASME tank, and when the original finally ages out, rusts, or fails, you are looking at a frame-mounted replacement rather than a bottle you swap.
The Manchester Tank ASME Permanent Horizontal Mount is the replacement I trust for motorhomes, and Manchester is the name many coaches were built with in the first place. At 24.2 gallons, it carries far more fuel than any pair of bottles, which is exactly why motorhome owners can run the furnace through a cold week without rationing.
Two things define this purchase. First, as an ASME tank, it is not subject to the DOT recertification cycle, so once it is in, the recertification clock that governs removable cylinders simply does not apply. Second, swapping an ASME tank is a job for a qualified propane technician, not a driveway project, between the fittings, leak testing, and mounting. Budget for professional installation as part of the purchase, and you will have a tank that serves for decades.
Buy Manchester Tank ASME Permanent Mount Propane Tank
Here is where people get caught out, often at the worst moment, standing at a fill station with an attendant shaking their head. Two rules govern whether your tank can legally be filled, and both are easy to stay ahead of once you know them.
The first is the valve. Modern DOT cylinders must have a Type 1 overflow protection valve, sometimes called an OPD. It is the current standard; it includes safety features that older valves lack, and it connects by hand without tools. Every new tank worth buying has one, and all three cylinders in this guide do. If a tank in your setup still wears an old-style valve, its replacement is overdue.
The second is recertification, and it applies only to DOT cylinders, not ASME tanks. A DOT cylinder has a manufacturer's date stamped into its collar, and after an initial period of twelve years, it must be recertified, then again periodically after that. Many stations will rightly refuse to fill an out-of-date cylinder. Before each season, glance at the date stamp on your bottles. If they are approaching that window, plan to recertify or replace rather than discovering the problem on a trip.
Neither rule is complicated, but both are absolute at the fill station. Buying a current tank with a Type 1 valve and keeping an eye on your recertification dates means you will never be the person turned away with an empty bottle.
It is worth knowing what recertification actually involves, so it feels less daunting. A certified facility inspects the cylinder for damage, corrosion, and valve condition, then stamps a new date if it passes. It is inexpensive and quick, where available, but availability varies by area, which is precisely why planning ahead matters; you do not want to learn your nearest facility is an hour away on the morning you are trying to leave. For many owners, once a cylinder reaches that first twelve-year mark, simply replacing it with a fresh tank carrying a new date is easier and not much more expensive than repeated recertification down the line.
The last piece is physical: where the tank goes and how it sits. Get this right before ordering, because a tank that does not fit your setup is no use, however good it is.
DOT cylinders are designed to be used in the vertical, upright position, which is how they sit in a trailer's tongue rack. The rack size also matters; a 30 lb cylinder needs a rack that accommodates it, so confirm your rack fits the size you are buying. If you are upgrading from 20 lb to 30 lb bottles, check the rack before you check out.
ASME tanks are mounted horizontally on the motorhome frame, and replacement is about matching the new tank to the existing mounting footprint and fittings. This is a large part of why professional installation matters: the tank has to fit the space and connect to the coach's propane system correctly.
A few minutes confirming your mounting situation, rack size for cylinders, and frame footprint for ASME tanks saves the frustration of a tank that will not fit where it needs to live.
If you tow in cold climates, give a thought to how the tank performs in low temperatures as well. Propane vaporizes more slowly when it is very cold, and a larger tank with more surface area and more liquid volume sustains a better draw for a hungry furnace on a frigid night than a small bottle does. This is another quiet argument for sizing up if winter camping is part of your plans, capacity buys you not just runtime but steadier performance when the temperature drops.
Beyond fit and function, the two tank types carry different long-term cost stories worth understanding before you buy. DOT cylinders are inexpensive to purchase and easy to replace, but they carry that recertification obligation, and a cylinder that ages out eventually needs recertifying or replacing. Over the long life of an RV, you may go through more than one set of cylinders.
ASME tanks cost considerably more up front and require professional installation, but they are essentially permanent. Free of the recertification cycle and built into the coach, a quality ASME tank can serve for decades without the periodic replacement cylinders may need. For a motorhome you plan to keep, that longevity offsets the higher initial outlay.
There is also a convenience dimension to the cost. With DOT cylinders, you do the work, lifting, transporting, and exchanging or filling them yourself, which costs time but keeps you in control and lets you top up anywhere. With an ASME tank, the fuel comes to you at a fill station, which is convenient but ties you to locations that can service a mounted tank. Neither is better in absolute terms; they simply suit different rigs and different owners.
Whichever tank you choose, a little protection keeps it serving reliably for its full life. For DOT cylinders riding on a trailer tongue, a tank cover is cheap insurance: sun, rain, and road grit all attack exposed cylinders and their valve hardware, and a cover shields the working parts so changeovers stay smooth and the tanks keep looking cared-for. It also helps resale, since clean, covered tanks signal an owner who looked after the details.
For both types, make a habit of a seasonal glance at the valve and connections. On cylinders, confirm the recertification date still has life in it, and the Type 1 valve operates smoothly. On ASME tanks, check that the fittings and the regulator are clean and corrosion-free. Catching a tired connection in the driveway beats discovering it at a fill station or, worse, on the road.
None of this is demanding: a cover, a yearly look, and attention to dates, but it is the difference between a propane system you trust completely and one that surprises you. The tank is the foundation of that system, and a well-chosen, well-protected tank quietly does its job for years.
Choosing an RV propane tank comes down to a short, logical chain of decisions. Identify your type first, DOT cylinder for trailers, ASME tank for motorhomes, since that single fact shapes everything else. Then size the tank to how you actually camp, insist on a current Type 1 valve, keep an eye on recertification dates for cylinders, and confirm your mounting before you buy.
For most trailer owners, that points to a quality cylinder in the right size, the Flame King 30 lb for cold-weather and longer trips, or the lighter King Flame 10 lb for smaller rigs and easier handling. Motorhome owners replacing an aging tank want the Manchester ASME permanent mount, installed by a professional.
Propane is the quiet workhorse of RV life, and a sound tank chosen correctly lets it stay that way: out of mind, ready whenever you cook, heat, or shower. Get the tank right once, and you can go back to thinking about the fun parts of the trip.
At RV Upgrades, we carry RV propane tanks in every size and type, from DOT cylinders to ASME permanent mounts, plus the valves, covers, and accessories to complete your setup. Explore our collection and find the right tank for your rig with confidence. Let us help you keep the burners lit all season long!
I’m Bill Rowell, the founder of RVupgrades.com. In 2002, I launched the business to help fellow RV enthusiasts find unique and hard-to-find products. Over the years, it’s grown to offer more than 15,000 items, with a warehouse in Eastlake, Ohio. Having owned and repaired nearly every type of RV, I bring over two decades of hands-on experience to the table. For me, this isn’t just a business – it’s a passion and a way of life that I love sharing with the RV community.
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