Where to refill RV propane on the road, and why a station might refuse your tank

Last verified: October 26, 2026

Disclosure: Some links on this site may be affiliate links; see our disclosure. We are not affiliated with any agency or company named here. Rules vary by state and by crossing, so check local rules and posted signs, and follow your RV owner's manual.

Cold nights are back, and RV forums and X are full of the same question: where do I fill up propane on the road, and why did that place turn my tank away? Here's what fire marshals, the U.S. DOT and the bridge and tunnel authorities actually say.

Where you can get propane

North Carolina's LP-gas regulators describe three ways to buy propane for a portable cylinder (the 20-lb kind most trailers carry): [1]

Exchange cabinets at convenience, grocery, big-box and hardware stores. They're the easiest to find at night or on weekends, but they often cost more per pound. Exchanged cylinders usually hold 15 to 17½ lb, and the net weight must be shown on the label or cabinet. [1]
Refill by the pound or gallon at propane companies, hardware stores and gas stations with a scale or meter. You pay for what goes in, and a nominal 20-lb cylinder should get 18–19 lb on a warm day. [1]
Flat-rate refills. You pay the same no matter how much was left in the tank, so you lose out if you top off a half-full cylinder. In North Carolina the flat price must be posted at the dispenser and at the register. [1]

Truck stops: Pilot's RV page advertises propane refill stations with "both cylinder and bulk propane refills." [2] Pilot says these are at participating locations, and not every location has every amenity. If your motorhome has a built-in tank, call ahead to confirm the stop can fill it. See our truck stop RV amenities guide.

Why a station will refuse to fill your cylinder

These rules are for DOT cylinders, the portable kind. DOT cylinders don't have an attached nameplate. A tank with an attached nameplate is an ASME container, which is a different type. [1][3]

The date stamp is too old. PHMSA (U.S. DOT): "Cylinders must be requalified within 12 years of manufacture." The manufacture date is stamped on the collar. If the cylinder is older than 12 years, look for a requalification date stamp or sticker. [3]
No OPD valve. All cylinders up to and including 40 lb propane capacity must have an Overfill Prevention Device. [1]
Damage. PHMSA says not to fill any cylinder with excessive rust, corrosion or pitting (especially near the bottom); dents, bulges, cuts or cracks; a missing or damaged foot ring, collar or valve cover; or a leaking or defective valve or relief device. [3]
It's a 1-lb camping cylinder. Ohio's State Fire Marshal: DOT 39 (1-lb camping) cylinders "are non-refillable and can rupture if refilled." [4]

In North Carolina, a location that turns your cylinder down must give you the reason in writing. The state warns against shopping around for someone who will fill it anyway. [1]

Reading the requalification marks

PHMSA's guide shows how long each type of requalification lasts: [3]

Mark after the date (example "4 22")	What it means	Next requalification due
No letter	Volumetric expansion test	Within 12 years
S	Proof pressure test	Within 10 years
E	Visual inspection only	Within 5 years

Requalification must be done by a DOT-approved requalifier, and not every filling location can do it. [1][3] The regulation is 49 CFR 180.209. [3][5]

How full is "full"?

For safety, a full cylinder is about 80% liquid, which leaves room for the propane to expand as it warms. The OPD stops the fill a little short of 20 lb on a warm day. [1] Ohio's fire marshal says not to fill beyond 80%. [4] Signs of an overfilled tank include a strong propane smell, liquid or vapor escaping, an OPD that has released, hissing, or a gauge reading high. If you suspect one, don't transport it. Move people away, eliminate ignition sources (including running engines), and call your propane supplier. [4] Keep cylinders upright and secured: a relief valve can release liquid propane if a tank is on its side. [4]

Bridges and tunnels: plan your route before you fill

Crossing	Propane rule (as officially stated)
Holland Tunnel, Lincoln Tunnel, George Washington Bridge lower level (NY–NJ)	Prohibited: RVs, campers and trailers "equipped with Liquefied Petroleum Gas installations for cooking, heating, or refrigeration." The rules add: "There is no 'Materials of Trade' exemption for propane. Vehicles carrying propane or propane tanks are prohibited." [6]
Fort McHenry Tunnel (I-95) and Baltimore Harbor Tunnel (I-895), MD	Vehicles carrying bottled propane "in excess of 10 pounds per container (maximum of 10 containers)" are prohibited. [7] Maryland's regulation allows propane in DOT-approved containers up to 10 lb gross per container and 100 lb gross per vehicle, and says flames used for heating must be put out before entering. [8] Unsure if your rig qualifies? Call MDTA, (410) 537-1000, before you go. [7]
Chesapeake Bay Bridge-Tunnel, VA	RVs and travel trailers are allowed, but "all propane must be turned off at the outside valve prior to crossing," and the vehicle is subject to inspection at the toll plaza. Maximum height is 13'-6". [9]

A standard 20-lb cylinder holds more than MDTA's stated 10-lb-per-container limit. [1][7] If you're running the I-95 corridor, check these rules before you top off your tanks.

Quick FAQ

My tank's collar says 10 15. Can I fill it in 2026?
Not without requalification. PHMSA says cylinders must be requalified within 12 years of manufacture, and October 2015 + 12 years is October 2027, so that one is still good until then. Anything with a collar date more than 12 years old needs a requalification mark first. [3]

Is exchanging cheaper than refilling?
Usually not. North Carolina says exchange often costs more, and an exchanged cylinder probably holds about 15 lb compared with 18–19 lb from a refill. [1]

Can I refill those green 1-lb bottles?
No. Ohio's fire marshal says they're non-refillable and can rupture. [4]

We don't list propane prices or claim any specific location has propane today. Prices and availability change; call ahead.

Sources

Sourced from the official agency and company pages listed above. Last verified October 26, 2026. This is general information, not legal advice. Follow your RV owner's manual, posted signs and local rules.