How Long Does Propane Last in RVs?

A house relies on natural gas piped in from a local gas company to operate some appliances. RVs, on the other hand, are engineered to deliver the same heating and cooking conveniences of home but in a mobile package. But how? For many campers, the answer is using propane, but if you’re new to RVing, you might wonder, “How long does propane last in RVs?” It’s a valid question and certainly a worthy consideration if you plan to do any RV boondocking. So, let’s investigate.

Why Do RVs Use Propane?

In many RV campers, major appliances like your water heater, furnace, cooktop and oven, and refrigerator are powered by the propane system. Although many modern campers now feature 12V refrigerators, running out of propane is still a major concern on longer trips. Knowing how RV propane systems work will help you estimate the amount of propane you’ll need on a trip so you don’t run out at the wrong time. By the end of this article, you’ll know how to troubleshoot why the propane is not flowing and solve issues on the fly.

So, why propane? Propane has a lower boiling point (-44 °F) than butane (31 °F), meaning it vaporizes more easily. For RVers, this allows you to use propane year-round, even for winter RV camping.

Some homes are powered by natural gas, which vaporizes at a lower temperature than propane (-259 °F). This chemical property makes natural gas unfeasible for portable applications. For commercial shipping, liquified natural gas must be stored in double-walled cryogenic containers. Of these combustible gases, propane is the safest and most practical for RVs.

When investigating propane alternatives, performance factors outside of transportability and vaporization are weighed:

• Heat production (temperature intensity)
• Cooking capacity (energy potential by volume)
• Combustion efficiency (range of flammability)
• Footprint considerations (lightweight and repair parts support)
• Eco-friendly, clean-burning fuel (greenhouse gas emissions per productivity unit)
• Budget constraints

How Long Does Propane Last in an RV?

Surprisingly, a propane leak is not the primary culprit for running out of propane. Usually, RVers simply underestimate propane consumption by forgetting to account for all propane-burning appliances or miscalculating propane usage hours. Knowing your propane usage rate will help you avoid running out. Use the following formulas to determine how much propane your RV system supplies. Compare that with your estimated propane consumption, and you’ll have a great estimate of how long propane will last on your next RV trip.

Propane is designated by gallons, pounds, and BTUs.

• Its liquid/liquified form is measured in gallons.
• Its vapor/gaseous form is measured in pounds.
• Its thermal production/reduction is measured in BTUs.

Key Propane Conversion Rates

• 4.2 pounds of gas = 1 gallon
• 21,548 BTUs = 1 pound of gas

Calculating How Long Propane Lasts in an RV

To determine propane consumption, refer to the numeric ratings of RV propane system components (propane containers, furnace, cooktop, oven, water heater, etc.) and plug those numbers into the following equations:

• Container BTUs = (container pounds x .80) x 21,548
  This converts the amount of propane into BTUs.
• Maximum BTUs = Add up the Container BTUs for all propane tanks
  This calculates the amount of BTUs your propane system is equipped with for operation.
• BTUs Per Hour = The model-specific amount of BTU gas input burned per hour
  If the appliance BTU rating is missing, use volts, amps, and watts to calculate:
  • BTUs Per Hour = Watts ÷ 3.413
  • BTUs Per Hour = (Volts x Amps) ÷ 3.413
• Total BTUs = Add up the BTUs Per Hour for each appliance
  This calculates the total BTUs burned for 1 continuous hour of operation.
• Baseline Consumption = Maximum BTUs — Total BTUs
  This calculates total propane consumption for each hour of continuous operation—assuming optimal efficiency.
• Available Usage Hours = Maximum BTUs ÷ Baseline Consumption
  This estimates how long the propane-burning appliances can operate.
• Planned Usage Hours = Number of hours
  This is the estimated amount of time you want to operate propane-burning appliances.
• Remaining Propane Available = Planned Usage Hours — Available Usage Hours
  This estimates how much propane is left to operate propane-burning appliances.

Technician Tip: If your Available Usage Hours exceed your Planned Usage Hours, you must carry more propane or schedule a refill.

Planning RV Propane Consumption

How many hours would you and your family generally run each RV appliance on a given day?

For a more accurate baseline, estimate planned usage based on your RV lifestyle. Make a detailed breakdown of Total BTUs by multiplying BTUs Per Hour by Planned Usage Hours for each appliance. If you’re a highly structured RVer or data-driven consumer:

• Rank your appliances by priority. This way, you’re prepared if you need to cut propane consumption.
• Chart your usage estimate around the anticipated activities for each day of a specific trip.
• Adjust future planned usage hours during your trip based on actual usage observations.

If you want complete confidence in how long propane will last in your RV, add a propane level monitoring device or an in-line RV propane gauge with a built-in propane leak detector to let you know when your propane container is running low.

The Basics of RV Propane Systems

Appliances burn gas, not liquid. However, transporting gas can be unsafe, so propane travels in liquid form for safety and convenience. Pressurization transforms the propane from a liquid to a gaseous state. Propane flows from the container through the propane lines to the appliance. Located along the propane lines are a combination of pressure regulators, which control and adjust the gas pressure to deliver a consistent flow at usable pressure for each connected appliance. Multiple safety components detect potential propane leaks in the system, such as excess flow valves, propane hose connection fittings, and pressure regulators.

RV Propane Containers

Propane is a type of liquified petroleum gas (LPG). As an LPG container, propane containers are subject to federal regulation and periodic recertification. The intervals are driven by the container’s original manufacture date and the most recently applied requalification method. There are two types of RV propane containers:

• Permanently Mounted RV Propane Tanks used in motorhomes are ASME-certified (American Society of Mechanical Engineers). ASME tanks vary in size.
• Portable RV Propane Cylinders typically used with travel trailers, fifth wheels, truck campers, and smaller motorhome conversions are DOT-certified (Department of Transportation) versions of the ones designed for backyard BBQs. The most common portable propane cylinder sizes are 5-gal and 7-gal (which are interchangeably referred to as 20 and 30-pound tanks, respectively). Gallons describe the liquid volume, while pounds describe the mass of its gaseous form.

Technician Tip: We’ll use ‘tank’ when referring to ASME tanks on motorhomes, ‘cylinder’ when referring to portable DOT cylinders in towable RVs, and ‘container’ when referencing both.

Refilling Propane Containers

Both types of RV propane containers are refillable. You can also exchange an empty portable propane cylinder for a full one. For safety, propane containers can only be filled to 80% to allow for gas expansion. To comply with this rule, RV propane containers manufactured after 1998 have an internal overfill valve preventing more than 80% liquid propane. You can verify whether your container is equipped with an overfill prevention device (OPD) by looking at its knob (tank valve). Across all manufacturers, the knob will be triangular-shaped and stamped “OPD” in contrast with the older non-compliant pinwheel or round-shaped knobs.

Some RVers wonder whether the marketed container size describes the amount of propane held when filled to 80% capacity. The safe bet is to check your specific container for stamped markings and labeling details. While this information is required, a standard for the uniform display of this data has not yet been established across all propane manufacturers.

RV Propane Regulators

Regulators are devices that reduce the high pressure coming from the propane tank to a pressure that is usable by your RV appliances. RV propane systems must use a two-stage RV propane regulator to control the system pressure. The first stage reduces the pressure to a consistent flow while the second stage further lowers the pressure to an appliance operating pressure. Additional regulators can also be designed into the propane line—either at the gas entry point or internal to the appliance—to closely control the propane pressure as it enters that appliance. If an RV propane regulator has gone bad, you may notice a rotten egg smell, and your system should be inspected by a certified RV technician immediately.

RV Propane Appliances

Propane-burning RV appliances are rated in BTUs per hour, a measurement of thermal energy. BTU input is the amount of energy an appliance requires to operate, while BTU output is the amount of energy delivered as heating or cooling. If the appliance operates at 100% efficiency, the input BTU rating would equal its output BTU rating.

Look at the label or technical manual to find the model-specific BTU ratings of your RV appliance. If the BTU rating is missing, you can calculate it using simple math. Take note of the watts or the volts and amps provided and plug into the Easy Math formula below.

Excess Flow Valves

Excess flow valves close automatically when they detect propane gas leaving the tank faster than the valve’s flow capacity rating. A pressure leak in the propane line would cause an elevated flow rate, triggering an excess flow valve. It’s important to remember that the excess flow valve may not detect all pressure leaks in the propane line due to the propane system configuration.

How To Find a Propane Leak in RVs

This is often an RVer’s first thought when the propane doesn’t last as long as expected. If your LP detector isn’t sounding the alarm and you don’t smell rotten eggs, the system is probably not leaking propane. Instead, it’s likely a performance issue causing a propane flow restriction or miscalculated propane consumption. However, propane gas is heavier than air. If the RV propane system is leaking, then the gas will settle to the ground, posing an inhalation hazard.

Inhaling propane gas displaces the oxygen in your lungs and can cause asphyxiation. Symptoms of propane inhalation include rapid breathing, rapid heart rate, clumsiness, nausea and vomiting, fatigue, collapse, and convulsions. Coma and death can occur from asphyxiation, even though propane is a non-toxic substance. In its natural state, propane is actually odorless. So, a chemical odorant called ethyl mercaptan is added to propane to give it that pungent rotten egg smell and help with leak detection. For these reasons, LP detectors are required with RVs (since 1996).

If you smell or hear either of those things, shut off the propane tank immediately and extinguish any open flames. Then, call a certified RV service professional to diagnose and repair the propane system. You can use the link below to find your local Camping World Service Center and inquire if they have a mobile technician or if you need to bring your camper in for an inspection.

Basic Troubleshooting for RV Propane Systems

First, check that your propane gauge is not sitting on empty and the valve is turned on. If equipped with an RV propane automatic changeover for dual containers, check whether the component malfunctioned. If the RV propane is not flowing to your appliances listed in the Venn Diagram above, follow the flowchart below:

Technician Tip: Before attempting to remove and replace damaged parts within your RV propane system, determine whether you have the skills, proper tools, and safety gear because of potential injury or explosion.

Environmental Factors

Take note of the ambient temperature, elevation, and propane level. These conditions affect your RV’s propane system performance. Liquifying pressure increases in colder weather and lower altitudes. Also, if the propane container is nearly empty in cold weather, the gases won’t expand enough to be extracted.

Control the temperature and propane level to optimize internal container pressure. To ensure the proper pressure inside the container, keep it warm with a propane blanket. Do not store the container in a heated living space for safety reasons. You can also replenish your propane more frequently to maintain an optimal fluid level. Optimizing your RV for propane conservation saves money in the long term for every season.

Excess Flow Valve

Check whether the excess flow valve in the propane hose is engaged. When connecting an RV propane container, the propane hose fitting may have been improperly threaded onto the container fitting. That prevents the spring mechanism of the excess flow valve from seating correctly. Disconnect the hose and reattach more carefully to avoid cross-threading.

Pressure Regulator

Inspect the RV propane pressure regulator for water damage, corrosion, or neglect. If the regulator looks fine, check around the burners (stove, furnace, water heater) for symptoms of an RV propane regulator problem—yellow or orange flames, soot build-up, roaring noise, or popping sounds. Caused by restricted propane flow, these symptoms indicate the excess flow valve inside the pressure regulator may have been triggered. If you do not see any of these symptoms, the valve may have been opened too quickly when turning on RV propane.

Make sure your appliances are shut off. Then, close the container valve so the pressure regulator resets itself. Wait 5-10 minutes before slowly opening the valve. This repressurizes the RV propane system.

Propane Hoses and Inline Valves

If the restricted propane flow symptoms continue after resetting the pressure regulator, then one or more propane lines may have a kink, or an inline RV propane valve may be closed. This depends on the type and placement of hoses and connectors used for your RV propane system configuration.

Further assistance with RV propane troubleshooting may require the expertise of a trained RV technician. Some Camping World locations offer Mobile Service, which makes it easy to get an LP system inspection without moving your RV. Others will require scheduling a service appointment and dropping your camper off. You can also call our Technical Service hotline with questions at 1-866-838-5304.

Or, ask us a question about how long propane will last in an RV or other troubleshooting issues in the comments below!