Among the many beneficial aspects of RVing is the ability to travel with various appliances that make RV life comfortable. Most RVs have some appliances that run entirely or partially on propane fuel, including the stove/oven, furnace, water heater, refrigerator, and in some cases, generators. Propane-fueled appliances are very efficient, but how long does a propane tank last when being used for RVing?
In today’s post, we’re addressing that very common question.
- 1) What Is a Propane Tank?
- 2) Are All RV Propane Tanks the Same?
- 3) What Size Propane Tanks Do RVs Have?
- 4) So, How Long Does an RV Propane Tank Last?
- 5) A General Guide for How Long RV Propane Lasts
- 6) How Can I Conserve Propane in an RV?
- 7) How Do I Know How Much Propane Is Left in My Tank?
What Is a Propane Tank?
A propane tank is a storage container used to hold liquefied petroleum gas (commonly referred to as LPG, or just LP).
They’re generally made of steel, though some smaller propane tanks may be made of aluminum or composite materials.
Propane tanks are specifically designed to contain propane at high pressures.
As we noted in our post “Does Propane Go Bad?,” propane tanks have expiration dates based on their date of manufacture. (The propane doesn’t expire but the tanks do.) They need to be inspected and either replaced or recertified as necessary.
Are All RV Propane Tanks the Same?
No – all propane tanks are not the same. Tank sizes vary widely to hold varying amounts of propane.
There are also two different types of propane tanks.
Built-in RV propane tanks such as those in motorhomes are generally ASME (American Society of Mechanic Engineers) tanks. These tanks are not portable or removable. They’re mounted horizontally to the outside or underside of the RV.
The size of ASME tanks varies widely. Some smaller motorhomes have a 20lb (5-gallon) or 33lb (7-gallon) tank, while larger Class A motorhomes can have ASME tanks that hold 80-100 pounds or more.
DOT Propane Cylinder Tanks
These are portable tanks that are generally 20lb (5-gallon) tanks and are not permanently built into the RV. These cylinders can be removed from the rig when they need to be refilled or replaced.
DOT cylinders need to be inspected regularly and either replaced or recertified every 12 years in the United States (every 10 years in Canada).
DOT propane cylinders can also be used with things like propane portable fire pits and grills.
Large propane tanks such as those for residential propane are much larger. 500-gallon tanks, for example, can hold sufficient liquid propane fuel to heat your home, run a large generator, provide fuel for a pool heater, and more. The size of this type of tank depends on the size of your home. The tank itself is delivered empty and then you contract with a delivery service for regular propane delivery.
An RV can be connected to a large propane tank, and many RVers who are stationary for extended periods of time do this. We’ve done this ourselves, in fact. We have a post on how we accomplished this: RV external propane connection.
What Size Propane Tanks Do RVs Have?
This actually varies considerably.
Most towable RVs and smaller campers will have one or two portable 20lb (5-gallon) DOT propane cylinders.
Class B RVs and some larger RVs may have slightly larger ASME propane tanks that are built-in. These generally are 33lb tanks that hold 7 gallons of LP.
Larger motorhomes usually have much larger built-in tanks, and those vary in size significantly, often up to 100lbs (25 gallons) or more. (Ours holds 32!)
By the way, you can connect your grill directly to your RV’s built-in ASME tank. See our post on our BBQ grill connection, where you’ll also find this video to watch Peter connect ours.
So, How Long Does an RV Propane Tank Last?
That’s a bit of a complicated question and we’ll tell you why.
While the average homeowner may have a 500-gallon propane tank and may use a certain amount of fuel based on the size of the home, RVs are much different.
For example, full-time RVers like us may have an average usage that we can calculate, but many RVers travel only for a weekend or a week at a time, and then not again for several weeks. Some RVers travel every weekend during the summer, but not at all during the rest of the year.
Meanwhile, different RVs have different propane appliances. Some use propane for a cooktop, water heater, and furnace, but they never use the furnace because they don’t travel when the weather is cold.
And then there’s the variation in the number of people traveling in the RV and using the appliances.
What all of this means is that propane usage varies greatly among RVers.
At the same time, propane tank sizes vary greatly on RVs. Our ASME tank may hold 32 gallons while another RVer’s single DOT cylinder holds 5 gallons.
So, there really is no universal answer to the question “How long does a propane tank last on an RV?”
Let’s quickly run through the most significant variables of propane use on an RV:
How Cold Is the Ambient Temperature?
Running your furnace uses propane much faster than just about any other activity. So if it’s very cold outside, you’re likely to use a lot more propane.
Also, if you’re connected to a city water supply in cold weather (or even if you’re using water from your fresh water tank), the water coming into your RV will be colder. This will mean more propane is required to heat the water to your desired temperature for showering, washing dishes, etc.
What Propane-Fueled Appliances Are You Using?
As noted above, the appliances you’re using will require varying amounts of propane to run.
- Furnace – uses the most propane
- Portable Propane Heater – much more efficient than a built-in furnace
- Stovetop and Oven – these generally use very little propane, but depends on how much and how long you cook
- Water Heater – depends how many showers are being taken and how frequently and how often dishes are washed. This also likely depends on how often you’re connected to shore power, since that adds the ability (in most RVs) to heat water with electricity instead of propane.
- RV Fridge – RV fridges sip propane and are very efficient
- Generator – some RVers travel with a generator that runs on propane, and of course will depend on how much you run it.
What Are the BTUs of Your RV Appliances?
BTU stands for British Thermal Unit and represents a unit of heat.
So, if your Class B RV has a 16,000 BTU LP gas furnace, and our Class A RV has a 30,000 BTU LP gas furnace, our furnace will burn more propane than yours will in the same amount of time.
But keep in mind that a smaller area (typical Class B rig) likely takes less time to warm up than a larger area (typical Class A rig).
The same is true for the fuel consumption of most RV appliances, so this is another variable of RV propane use.
A General Guide for How Long RV Propane Lasts
One way to gauge how long your RV propane tank will last is to calculate your usage based on the following information:
One gallon of propane generally lasts around 95 hours when used at a rate of 1,000 BTUs an hour.
Therefore, if our rig has a furnace rated at 30,000 BTUs, then a single gallon of propane should last around 3.17 hours. If you have a 5-gallon cylinder, you should be able to run a 30,000-BTU furnace for 15.85 hours.
However, these examples assume you’re using your propane for nothing else which is unlikely to be the case. They also assume that the furnace is running constantly which would very rarely be the case since the furnace will cycle on and off as the temperature in the space rises and falls.
If you’re also running a fridge and water heater, you’ll need to adjust your expectations accordingly.
To offer some additional information that you can use to gauge the amount of propane fuel you’re most likely to use while you’re RVing, we direct you to our posts “How Much Propane Does an RV Furnace Use?“, and “How Much Propane Does an RV Fridge Use?”
This cool “Propane Burn Time Calculator” may also be something you can use to help determine how long your propane tank will last based on your propane use. Simply enter the BTU rating of your propane appliance and the size of your propane tank.
Remember, though, you’ve got to consider all of the variables we mentioned above and use them to calculate your full usage.
How Can I Conserve Propane in an RV?
There are several things you can do to conserve the propane use in your RV.
Use a Propane Space Heater
Small propane space heaters are far more efficient than large RV furnaces. Using a small space heater to warm the area of the RV where you spend the most time will help to conserve the propane in your tank.
For more information on the safety of this approach to conserving propane, see our recent post entitled “Can You Use a Propane Heater Indoors?”
Use RV Skirting When Stationary in Winter
If you’re stationary in your RV during the cold months, you could use RV skirting for winter to keep the underside of your rig – and therefore the rig itself – warmer.
RV skirting helps to block the wind and acts as an insulating factor under the rig, holding your RV’s heat inside where it belongs.
Time Use of Hot Water for Dishes and Showers
Rather than allowing the water in your water heater to cool and heat over and over again, time showers and doing dishes to coincide with particular times of the day when you’ll run your water heater.
Warm Up Without the Furnace
If there’s just a chill in the air and not a full-on deep freeze, choose an alternative to running the furnace such as a battery-operated heating blanket.
Cook Over a Fire
If you’re camping in lovely weather, you can conserve some propane by cooking your dinner over a campfire rather than using the gas stove and/or oven.
How Do I Know How Much Propane Is Left in My Tank?
If your propane tank doesn’t have a working gauge, there are a couple of things you can do to monitor the fuel level in the tank.
One thing you can do is buy a gauge for your tank, of course. This one is especially nice because it also offers leak detection. It’s appropriate for DOT propane cylinders.
- Type 1 connection for gas grills, RVs and boats
- Fits a DOT propane cylinder manufactured after 1995 that have the ACME/OPD connection
There are gauges for ASME tanks that you can buy based on the manufacturer of your tank.
If you don’t have a gauge for your propane tank and want to know how much propane is left, we’ll let Peter show you how to do that – it’s easy!
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Sunday 9th of October 2022
I must take exception to your statement "RV fridges sip propane and are very efficient". They may "sip propane" but they are not very efficient compared to a compressor type fridge. In another one of your articles, you state "Dometic’s DM 2882 rated at 1,500 BTUs per hour" and is a new very efficient fridge. 1 watt of electricity consumed for one hour = 3.41 BTUs. Therefore your efficient DM 2882 would consume 1,500 / 3.41 = 440 watts continuously for per hour. The several RV fridges I've seen show 600 watts on 120VAC and 300 watts on 12VDC. The DC operation can only maintain temperature, not cool additional items, hence the lower power. The duty cycle being 85-90% at 25C ambient, so it runs continuously at 30C. I use an apartment size 7.5 cu.ft 120VAC fridge in my motorhome (less than $400). It consumes 90 watts while running (RV compressor fridges run about 60 watts), and runs less often (20-30 minutes per hour depending on outside air temperature. Therefore 90/50% duty cycle = 45watt hrs or about 10% of the absorption fridge power consumption. So its like comparing LED lights to incandescent. The only reason an absorption fridge "appears" to be efficient is because propane has a much higher energy density than a battery. One US gallon of propane = approximately 92,000 BTUs while a 100 AmpHr LiFePO4 battery is 1,280 WattHrs x 3.41 = 4,365 BTUs. So a gallon of propane has about 20 times the energy compared to a standard LiFePO4 battery. I'm sure someone can make some clarifications.
Saturday 8th of October 2022
Thank you gor this information. You stated that we should use a small portable heater to save propane. Mycquestion is don't we have to run the furnace to protect the lines under the floor?
Monday 10th of October 2022
Hi Mike. Yes… if outside temps are going to go low enough that you’re at risk of plumbing freezing, you need to use the furnace to pump some heat into the basement and water compartments. But there are plenty of other times when it’s cold enough to use heat, and running a space heater saves your propane (for when you REALLY need it)!
Saturday 8th of October 2022
You can only fill a propane tank to about 80% full. Therefore you only get about 4 lbs of propane in a 20 lb tank. Blue Rhino only fills to 15 lbs or 3.65 gallons.