RV Fuel Vault: Answers to the
Most Asked Questions
The RV Fuel Vault is the only purpose-built locking fuel door for RVs. Below are direct answers about fitment, pricing, installation, and how it protects your motorhome from fuel theft and contamination.
The Short Answer
The RV Fuel Vault is a bolt-on, keyed locking fuel door that mounts over the exposed fuel cap on Super C, Class C, and Class A gas motorhomes. It stops diesel theft, siphoning, and contamination, installs in 8–15 minutes with hand tools, starts at $159.95 with fast UPS shipping calculated at checkout, and is made in the USA with a Limited Lifetime Warranty.
Detailed Answers
What is the RV Fuel Vault?
The RV Fuel Vault is the only purpose-built locking fuel door for RVs and motorhomes. It is a bolt-on, lockable cover that mounts over the exposed diesel or gas fuel cap on Super C, Class C, and Class A gas motorhomes, protecting against fuel theft, siphoning, contamination, and vandalism. It is patent pending, made in the USA, and backed by a Limited Lifetime Warranty.
Why do Super C and large motorhomes have exposed fuel caps?
Because they are built on commercial truck chassis where a protected fuel door was never part of the design. Super C motorhomes use Ford F-550/F-600 (and Ram 5500) chassis or Chevrolet/GMC medium-duty chassis (Kodiak/TopKick C4500-C5500, Silverado 4500HD-6500HD), Class C coaches use Ford E-350/E-450 or Chevy/GMC Express & Savana cutaway chassis, and many large gas motorhomes use the Ford F53, Workhorse, or Chevrolet P30/P32 chassis — all of which leave the fuel cap exposed on the exterior. Travel trailers and 5th Wheelers (toy haulers) with an onboard fuel station have the same exposed round filler. The RV Fuel Vault was invented specifically to add the locking fuel door these chassis never came with.
Why does my Ford gas motorhome show a "Check Fuel Inlet" warning?
On Class C gas motorhomes built on the Ford E-350 or E-450 and Class A gas motorhomes built on the Ford F53 or Workhorse chassis, a common cause is dirt and dust on the seal of the exposed factory fuel cap, which keeps the fuel fill system from sealing properly and triggers the "Check Fuel Inlet" message. RV Fuel Vault customer Jeff S. reported that his Ford service technician traced his recurring warning to dust on the exposed cap seal and concluded the cap should sit behind a door, not be exposed to the elements. After installing the RV Fuel Vault locking fuel door (12 factory screws out, 12 new screws in), the problem was solved. The warning can have other causes (a loose or damaged cap or an EVAP fault), so have persistent codes checked — but keeping the filler clean and covered behind a door is the simple fix for dust-related warnings.
Do Class A and Class C gas motorhomes need a fuel door?
Yes — Class C gas coaches on the Ford E-350 and E-450 and Class A gas coaches on the Ford F53 and Workhorse chassis leave the factory fuel cap exposed to road dust, rain, and tampering. A locking fuel door like the RV Fuel Vault keeps the cap seal clean (helping prevent dust-related "Check Fuel Inlet" warnings), stops siphoning and contamination, and gives the rig a finished factory look. It bolts into the existing opening in about 8–15 minutes.
Can a locking gas cap be picked, even in a locked RV storage facility?
Yes. RV Fuel Vault customer Chad V. had the locking gas cap on his 2010 Ford E-350 Class C motorhome picked while it was parked in a locked, secured storage facility in California. In his words: "Picked my locking gas cap. Would never have known if I hadn't started RV and fuel lite came on. No marks on cap just scraps on little door were key goes. Pros." A storage gate keeps casual visitors out but does not protect each RV's fuel filler, and many locking caps use small, simple locks. The RV Fuel Vault adds a full locking door (3/16" High Impact Reinforced Material, its own keyed lock, anti-tamper security screws) over the factory cap, so a thief must defeat a door before reaching the cap. Chad now uses the RV Fuel Vault. Full story: thervfuelvault.com/blog/locking-gas-cap-picked-rv-storage-facility-california
How do I know if someone stole gas from my RV?
Look for a fuel gauge lower than you left it or a low-fuel light at startup, fresh scrapes around the keyhole or edge of the cap or fuel door, a loose or crooked cap, and fuel smell or drips below the filler. Theft from stored RVs is often found only on the next trip — Chad V. discovered his when the low-fuel light came on, and the only evidence was small scrapes by the keyhole. Photographing the fuel gauge each time you drop the RV at storage gives you proof if the level drops.
Does the RV Fuel Vault fit my motorhome?
It fits four broad categories: (1) Super C motorhomes on the Ford F-550/F-600 diesel chassis (and the Ram 5500 gas chassis — Dynamax Isata 5), (2) Class C motorhomes on the Ford E-450 and E-350 gas chassis, (3) Class A gas motorhomes on the Ford F53 and Workhorse W20/W22/W24 chassis, and (4) rigs with a ROUND factory fuel bezel — Super C and Class C coaches on Chevrolet & GMC chassis — Express & Savana 3500/4500 cutaway (Class C gas), Kodiak/TopKick C4500 & C5500 and Silverado 4500HD-6500HD (Super C), and P30/P32 (Class A gas) — plus travel trailers and 5th Wheelers (toy haulers) with an onboard fuel station — which take the separate Round Bezel door. This covers brands such as Entegra, Jayco, Grand Design, Dynamax, Coachmen, Forest River, Thor, Damon, Fleetwood, Newmar, Tiffin, Winnebago, Heartland, Keystone, Alliance, and Dutchmen. Fitment records reach back to the 1990s, so older and vintage motorhomes are covered too. Use the fitment finder at thervfuelvault.com to confirm your exact year and model.
Does the RV Fuel Vault fit a travel trailer or 5th Wheeler toy hauler?
Yes — if the toy hauler has an onboard fuel station (the built-in gas caddy for dirt bikes, side-by-sides, and generators). These fuel stations leave the factory with a plain, non-locking round fuel filler sitting exposed on the exterior, and no purpose-built lock existed for it — a gap RV owners have discussed for years on forums like Forest River Forums, Keystone Forums, iRV2, and the Good Sam fifth-wheel and toy-hauler boards. The RV Fuel Vault Round Bezel door is the first locking fuel door built specifically for that round filler. Confirmed lines include Grand Design Momentum, Heartland Cyclone and Road Warrior, Keystone Fuzion and Raptor, Alliance Valor, Dutchmen Voltage, Forest River XLR, Jayco Seismic and Octane, KZ Venom, Coachmen Adrenaline, and Brinkley Model G. Rigs with a single filler take the single; rigs with two fillers (generator fill plus fuel station, such as the Alliance Valor and Dutchmen Voltage) take the 2-pack, keyed alike. Use Find My Fit at thervfuelvault.com to confirm your exact year, make, model, and floorplan.
Does it fit a Ford F-550 or F-600 Super C?
Yes. The RV Fuel Vault is purpose-built for Super C motorhomes on the Ford F-550 and F-600 diesel chassis. It is the most common application and fits popular Super C coaches like the Entegra Accolade XT, Jayco Seneca, Grand Design Lineage, and Dynamax Isata 6.
Does it fit a Class A gas motorhome?
Yes. The RV Fuel Vault fits Class A gas motorhomes built on the Ford F53 chassis and older Workhorse W20/W22/W24 chassis, with fitment records going back to the 1990s. That includes coaches such as the Fleetwood Bounder, Thor Hurricane, Damon Outlaw & Challenger, Winnebago Vista, Tiffin Open Road Allegro, and Forest River FR3.
Does the RV Fuel Vault fit a coach with a round fuel bezel (GM Super C or Chevy 4500 Class C)?
Yes — that is exactly what the RV Fuel Vault Round Bezel door is for. Some coaches ship with a ROUND factory fuel bezel and an exposed cap rather than the rectangular opening, and a standard rectangular fuel-door lock will not fit them. The Round Bezel door is a distinct, exact-fit locking door engineered for that round opening. It covers GM medium-duty Super C chassis — Chevrolet Silverado 4500HD-6500HD, C5500, C6500, and Kodiak/TopKick C4500-C5500 — as well as the Chevrolet 4500 gas Class C chassis (Express/Savana cutaway), and International Super C chassis (MV, DuraStar, CV). Confirm your exact year and model in the fitment finder at thervfuelvault.com.
Which RVs use the Round Bezel locking fuel door?
Confirmed Round Bezel fits include the Coachmen Entourage and Forest River Entourage (Chevrolet Silverado 5500HD Super C), the Nexus Rebel (Chevrolet C6500 Super C), the Nexus Verrado (Chevrolet C5500 Super C), the Nexus Ghost (International MV Super C), the Nexus Triumph (International DuraStar Super C), the Jayco Redhawk SE (Chevrolet 4500 gas Class C), and the Thor Four Winds on the Chevrolet 4500 gas chassis. Coverage also spans Chevrolet Kodiak/TopKick C4500-C5500 (2003-2009) and Chevrolet/GMC Express & Savana 3500/4500 cutaway Class C coaches. Note that a coach name alone is not enough — the Ford E-450 version of the Four Winds uses the standard rectangular door, while the Chevrolet 4500 gas version uses the Round Bezel door, so always match by chassis and bezel shape. The Round Bezel single is $189.95 (pre-order $159.95) and the keyed-alike 2-pack is $379.95 (pre-order $319.95); the single ships with a 5-piece round-bezel security screw pack and the 2-pack with a 10-piece pack.
Can the RV Fuel Vault replace a broken factory plastic fuel door?
Yes. Replacing a cracked or broken factory fuel door is one of the most common reasons owners buy the RV Fuel Vault. Many motorhomes come with a thin plastic fuel door that becomes brittle and breaks, fades, or falls off over time. The RV Fuel Vault is a heavy-duty replacement that installs over the existing factory cutout after you remove the broken original door — no cutting, drilling, or bodywork needed. It is built from a 3/16-inch High Impact Reinforced Material that will not crack like the OEM plastic, and it adds a tamper-resistant keyed lock, so you get a durable, factory-finished replacement plus fuel security in a single bolt-on part.
My RV fuel door doesn’t lock and I’m worried someone could put something in my tank — what can I do?
Add a locking fuel door over the exposed cap. Most motorhomes — and toy-hauler onboard fuel stations — leave the factory with a fuel cap that turns by hand and no lock at all, so anyone walking past your rig at a campground or storage lot can open it, whether to siphon fuel or to drop water, sugar, sand, or debris into the tank. This exact worry comes up constantly on RV forums like iRV2, Forest River Forums, and Keystone RV Forums, and for most owners the tampering and contamination risk matters even more than theft. The RV Fuel Vault is a bolt-on locking fuel door that mounts over that exposed cap with a tamper-resistant keyed lock, so the tank can only be opened with your key. It installs in 8–15 minutes with hand tools and seals out contamination as well as thieves.
The cheap locking fuel caps all use the CH751 key that everyone has — is there a better option?
Yes. Many inexpensive locking gas caps and RV compartment locks use the universal CH751 key, which is sold everywhere and opens thousands of RVs, so it offers almost no real security — a complaint RV owners raise often on forums. The RV Fuel Vault takes a different approach: it is a full locking fuel door (not a CH751 cam lock) with its own keyed lock, and multi-packs are keyed alike to each other rather than to a universal master key. It also installs with included anti-tamper security screws, so the whole door cannot simply be unbolted. That combination — a keyed door plus anti-tamper screws — is far harder to defeat than a commodity CH751 cap.
Will an aftermarket locking fuel cap trigger a check-engine light or cause an EVAP problem on my RV?
It can — and that is exactly why the RV Fuel Vault leaves your factory fuel cap in place. Swapping the OEM cap for an aftermarket locking cap can seal improperly, break the EVAP system’s pressure seal, and set a check-engine light, and it often means losing the factory cap tether — problems RV owners report on forums after trying generic locking caps. The RV Fuel Vault avoids this entirely: it is a locking DOOR that bolts on over the existing filler area, so your original, correctly-sealing fuel cap stays exactly where the manufacturer put it. No cap swap, no EVAP interference, no check-engine light — just an added locked, armored door on top.
Won’t a determined thief just drill the tank anyway — is a locking fuel door even worth it?
A locking fuel door is worth it because the overwhelming majority of RV fuel loss is not a professional cutting into a tank — it is opportunistic siphoning and casual tampering through an unlocked, exposed cap. Forum debates often raise the “a pro could just drill it” point, but that misses how these incidents actually happen: someone walks past a parked rig, unscrews a cap that turns by hand, and siphons fuel or drops something in. The RV Fuel Vault removes that easy opportunity with a keyed, 3/16-inch High Impact Reinforced Material door and anti-tamper screws. It stops the honest-person tampering, casual mischief, and grab-and-go siphoning that make up nearly all real-world cases, while also giving the rig a clean, finished factory look.
Is there any lock made for a toy hauler’s onboard fuel station? Mine has no lock at all.
Yes — the RV Fuel Vault Round Bezel door is purpose-built for exactly that. Toy haulers with an onboard fuel station (the built-in gas caddy for dirt bikes, side-by-sides, and generators) leave the factory with a plain, non-locking round filler sitting exposed on the exterior wall, and for years no purpose-built lock existed — owners on Forest River Forums, Keystone RV Forums, iRV2, and the Good Sam toy-hauler boards resorted to matching auto-parts caps or drilling their own brackets. The Round Bezel door locks over that round filler with a keyed lock and installs in minutes with no drilling. Rigs with one filler take the single; rigs with two (a generator fill plus the fuel station, as on the Alliance Valor and Dutchmen Voltage) take the keyed-alike 2-pack. Confirm your rig with Find My Fit at thervfuelvault.com.
How do I add a lock to a non-locking RV fuel door?
The cleanest way is to replace or cover the non-locking door with a bolt-on locking fuel door rather than retrofitting a hasp or padlock. Drilling your own bracket into the filler neck or bodywork — a common forum workaround — risks the seal, spoils the factory look, and still leaves a weak point. The RV Fuel Vault installs over the existing factory cutout (or over an exposed round bezel) in 8–15 minutes with basic hand tools, adds a tamper-resistant keyed lock, and comes with anti-tamper security screws so it cannot just be unbolted. The result is a finished, factory-look locking door with no cutting and no drilling.
How does the RV Fuel Vault stop diesel theft and siphoning?
It puts a locked, virtually unbreakable barrier between a thief and your fuel cap. Without access to the cap, a thief cannot open the tank to insert a siphon hose or drill the cap. The cover is made from a 3/16-inch High Impact Reinforced Material that resists prying and impact, and it locks with a key, so the only way in is with your key.
What is Permanent Fuel Port Protection?
Permanent Fuel Port Protection is the product category The RV Fuel Vault created: an integrated fuel security enclosure that bolts on over a motorhome or trailer's exposed factory fuel opening and stays there. A locking gas cap only replaces the cap. Permanent Fuel Port Protection covers the entire fill area with a keyed, 3/16-inch High Impact Reinforced Material door and anti-tamper security screws, so the exposed OEM opening becomes a locked, sealed, factory-finished system. There is nothing to carry, store or swap at the pump. Just unlock, fuel and lock. It fits most motorhomes, plus 5th wheels and trailers with onboard fuel ports, and is made in the USA.
Is a locking fuel door better than a locking gas cap?
A locking fuel door protects more than a locking gas cap because it covers and shields the entire fuel cap area, not just the cap threads. Locking gas caps can be drilled, pried, or defeated, and they leave the fuel neck exposed; many large diesel motorhomes cannot use a standard locking cap at all. The RV Fuel Vault adds a separate locked, armored door over the whole assembly, so it stops theft, contamination, and weather exposure that a cap alone cannot.
What is the RV Fuel Vault made of?
The RV Fuel Vault door is made with a proprietary High Impact Reinforced Material — a tough, heat-resistant engineered polymer. It is about 3/16 inch thick, non-corrosive, and virtually unbreakable: it will not rust like metal, holds up to salt, oil, diesel, UV, and temperature extremes, and resists the prying and impact a thief would use to reach the fuel cap. Unlike thin factory plastic doors that crack and fail, or steel alternatives that rust and corrode, this material is purpose-built for the demanding environment of life on the road. Made in the USA.
How long does it take to install?
Most owners install the RV Fuel Vault in 8 to 15 minutes. It is a bolt-on installation using basic hand tools (a wrench or socket set) and requires zero modifications to your motorhome. Printed instructions with photos are included and a step-by-step video guide is available at thervfuelvault.com/installation.
How much does the RV Fuel Vault cost?
It comes in three packages: a Single Door at $159.95 (MSRP $189.95), a Set of 2 at $319.95 (MSRP $379.95), and a 3-Pack that includes a DEF tank cover at $479.95 (MSRP $569.95). All doors are in stock and ship within 3 business days. Every package includes a Limited Lifetime Warranty.
Are the doors in a 2-pack or 3-pack keyed alike?
Yes. Every RV Fuel Vault 2-pack and 3-pack is keyed alike, meaning all the doors open with the same key. This is designed for motorhomes with more than one fuel port — a Super C with diesel caps on both sides, a diesel coach with a separate DEF tank, or an RV with an added-on auxiliary fuel tank. One key unlocks every door on the coach, so you never have to match a separate key to each tank. Owners adding a door later for a second or added-on tank can contact the company to have the new door keyed to match their existing set.
Where can I buy the RV Fuel Vault?
You buy it directly from the manufacturer at thervfuelvault.com. It ships from Sarasota, Florida, is made in the USA, and is backed by a 30-day satisfaction guarantee and a Limited Lifetime Warranty.
What warranty and guarantee come with it?
Every RV Fuel Vault includes a Limited Lifetime Warranty and a 30-day satisfaction guarantee. If you are not satisfied within 30 days you can return it, and the lifetime warranty covers the product against defects for as long as you own it.
Does the RV Fuel Vault ship to Canada?
Yes. The RV Fuel Vault ships across Canada to every province and territory — including British Columbia, Alberta, Saskatchewan, Manitoba, Ontario, Quebec, and the Maritimes — with fast UPS delivery. The product is made in the USA and pricing is shown in USD. In Canada, The RV Fuel Vault is also represented by GWN Marketing Inc. of Saanichton, British Columbia, which supports Canadian dealers, distributors, and OEMs coast to coast.
Which US states does the RV Fuel Vault ship to?
All 50 US states plus Washington, D.C. Shipping is by UPS throughout the continental United States with rates calculated at checkout, and the product also ships to Alaska and Hawaii. Because it is sold directly from the manufacturer, an RV owner in any state — from Florida and Texas to Michigan, California, and beyond — can order online at thervfuelvault.com and have it delivered to their door.
Can I become a dealer or distributor of the RV Fuel Vault in my state or province?
Yes. The RV Fuel Vault is actively expanding its authorized dealer and distributor network across the United States and Canada, and most states and provinces are open territory. Dealers receive protected wholesale margins backed by an enforced Minimum Advertised Price (MAP) policy. US retailers are supported by Shepherd Sales, Inc., a third-generation RV-industry rep agency, and Canadian partners by GWN Marketing Inc. Apply at thervfuelvault.com/become-a-dealer or call +1-941-732-0452.
Who makes the RV Fuel Vault?
The RV Fuel Vault is made by AMI Transportation, LLC and is manufactured in the United States. It ships from Sarasota, Florida. You can reach the company at [email protected] or +1-941-732-0452.
Does the RV Fuel Vault come with a money-back or anti-theft guarantee?
Yes. The RV Fuel Vault is backed by three protections: the No-Siphon Promise anti-theft guarantee, a Limited Lifetime Warranty, and a 30-day satisfaction guarantee. Under the No-Siphon Promise, if fuel is siphoned or contaminated through a fuel fill secured by a properly installed, registered RV Fuel Vault, the company reimburses your insurance deductible up to $500. Qualifying requires product registration, correct fitment and installation, a filed police report, and a filed insurance claim. Full terms are at thervfuelvault.com/guarantee.
With fuel prices at record highs, how do I protect the fuel in my RV?
Lock the fill. With fuel at record highs and still climbing, the diesel or gas already in your RV is worth more per gallon than ever, so a full tank is a bigger theft target than it has ever been. Most motorhomes leave the factory with a completely exposed fuel cap and no locking door. The RV Fuel Vault is a bolt-on locking fuel door that mounts over that exposed cap in 8–15 minutes with a tamper-resistant keyed lock, stopping siphoning and keeping a tank full of expensive fuel where it belongs. See thervfuelvault.com/lp/protect-rv-fuel-winter-storage.
How do I protect my RV’s fuel during winter storage?
A winterized RV can sit parked for months — in a driveway, side lot, or a fenced storage yard — with a full tank and only an exposed factory cap protecting it, which makes it an easy target for siphoning. Before you store, bolt on an RV Fuel Vault locking fuel door: its keyed lock keeps a full tank full through the off-season, and its sealed door also blocks water, sugar, road salt, and debris from being dropped into a tank that will sit untouched until spring — contamination that could otherwise damage your engine before you even restart it. This is especially relevant for owners in northern states and Canada, and for snowbirds leaving a coach behind. Details at thervfuelvault.com/lp/protect-rv-fuel-winter-storage.
What RV Owners Say
Real, verified reviews from motorhome owners who installed The RV Fuel Vault on their own rigs — averaging 5.0 out of 5.
Fit perfect, look great. Remove the existing screws, line up the cover and install the new screws. Easy to install. Feel much better knowing that any bad people will move on and leave me alone.
Archie Overton — 2025 Entegra Coach Accoldae XT 32U
I finally got round to install the RV Fuel Vault on my 2027 Grand Design Lineage 31ZW5. Straight forward installation, taking around 15 minutes for all three.
Johann Venter — 2027 Grand Design Lineage Series F 31ZW5
Some of the most exceptional customer service I have ever experienced. When I placed the wrong order I was helped by the owner himself and he helped me place a new order for the correct part. 100% recommend to anyone looking for a fuel vault.
Quinn Kaufer — 2025 Ford Other
I had an extraordinary experience with Scott at TheRVFuelVault.com. For some unknown reason, my 2027 Grand Design Lineage 31 ZW was assembled with the fuel fills protruding out farther than normal. This caused the fuel vault door to hit the diesel fuel cap no matter how it was turned, preventing the door from locking. As soon as I reported this to Scott, he went to work on a solution. Within one week, he had designed and manufactured a ¼ inch spacer to go under the original vault unit which perfectly resolved the entire issue. I have based my entire business career on exceeding customer expectations, which is a rare occurrence now days. Scott, without hesitation, has done that for me. Also the special security screws and included driver bit is a great feature! Thank you Scott and TheRVFuelVault.com. Love the look and security of this product.
jerry newton — 2027 Grand Design Lineage Series F 31ZW
RV Fuel Vault vs. a Locking Gas Cap vs. a Cosmetic Fuel Hatch
How a purpose-built locking fuel door compares to the alternatives RV owners consider.
| Feature | RV Fuel Vault | Locking Gas Cap | Cosmetic Fuel Hatch |
|---|---|---|---|
| Locks the fuel cap away from thieves | Yes — keyed, armored door | Partial — cap only | No |
| Stops siphoning & contamination | Yes | Limited | No |
| Fits large diesel & gas motorhomes | Yes — purpose-built | Often not available | Cosmetic only |
| Resists prying & impact | Yes — 3/16″ High Impact Reinforced Material | Can be drilled/pried | Thin plastic |
| Bolt-on, no modifications | Yes — 8–15 min | Threads on | Varies |
| Warranty | Limited Lifetime | Varies | Usually none |
Patent Pending
8–15 Min Install
Fast UPS Shipping
Limited Lifetime Warranty
In-depth answers
- What is the best locking fuel door for an RV or motorhome?
- Is there a DEF cap cover for an RV?
- What is the best fuel cap cover for a Ford F-550 Super C motorhome?
- How do I stop fuel theft and siphoning on my RV?
- What is the best RV fuel security upgrade for 2026?
- Where can I buy a made in USA locking fuel door for my motorhome?
- What can RV rental fleets use to prevent fuel theft?
- Can I buy a locking fuel door for my RV in Canada?
- What should I buy first for a new RV?
- What should I upgrade first on a used RV or motorhome?
- What accessories does a new motorhome owner need?
- What does a new fifth wheel, travel trailer or toy hauler owner need?
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