What Happens When RV Furnace Runs Out Of Propane? The Best Answer

If you’re an avid camper, you know the importance of a full propane tank, especially when it’s cold outside. Whether camping for the weekend or taking a longer excursion, having a reliable fuel source for your furnace is essential.

So what happens to your RV furnace when the propane runs out? The post below will explain what will happen and what your options are.

First, you need to check if you are indeed out of fuel or if it is another issue. Sometimes what may seem like a propane issue may be something else. Just like if your car stalls while driving, it may or may not be low fuel, but a variety of other problems may cause the same issue.

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Propane Supply

Propane tanks come in various sizes and hold anywhere from 20 to 100 gallons of fuel. When talking about a camper propane tank, these are usually figured by weight and not the gallon. For example, the typical propane tank you see for a BBQ is a 20lb tank. Generally, your camper is likely a 20 lb or 30 lb tank. This is a great size as it is mobile, and you can get a propane refill at many locations.

Depending on usage and temperature outside, a full 20 lb tank should be able to power an RV furnace for around 12-14 hours when running at maximum capacity. However, if you regulate your thermostat or reduce your furnace usage, the tank should last significantly longer than that!

Are You Out of Propane?

Anytime you think you are out of propane gas, I suggest you test other propane appliances to see if these are working. A quick and simple way is to see if you have propane on your stove. Most stoves do run on propane, and if you can see a blue flame and it looked to operate normally, then you likely still have some propane in your tank.

If your stove still works, you still have propane

You can do this with any other propane appliance, such as a hot water heater. If you are still getting hot water, this will confirm that you have some fuel in the tank.

Do You have a Propane Leak?

Another thing to check for is to see if it makes sense that you are low on fuel with your propane usage. For example, if you just filled your tanks, and now the tanks are empty, you should check for leaks. The reason for this is for safety, but also, you don’t want to do a propane refill and have it quickly empty again.

Do a basic visual inspection of the propane system. This includes looking for areas with a gas leak. This could include the gas line, valve, and propane regulator. Check real close at fitting and connections, as this is where most gas leaks can occur.

As you inspect, if you smell any propane, first visit Propane Smell Outside RV to detect and fix the leak.

What Happens to RV Furnace?

So your furnace was running and giving heat, but now all you have is cold air? Your RV furnace has a series of safety checks, and if any of them are not met, the system will turn off to protect the appliance and the people in the camper.

As the fuel runs out in the tank, the furnace will detect that their is no more fuel being burned or heat being produced. This will send the furnace into a safety mode that will shut the unit off.

What will happen is that the furnace fan will run for about 30 seconds, and then it will turn itself off. You can also turn the furnace off and on, and it will try again – first by starting the blower. If there is no fuel and no heat detected, the furnace will shut off. There is more info on my post for what to do when your RV heater turns off after 30 seconds.

What To Do?

The easy choice is to get more propane. However, the reality is that your furnace runs mostly at night and will likely go out in the middle of the night while the propane supplier is closed.

If you have shore power, I would always pack and keep an electric heater nearby in the camper. If it’s 2 am and your tank has no more fuel, plugging in an electric space heater should get you through the night until you can refill your propane tank in the morning.

Small portable heaters can be used – but read the owners manual for safety

What happens if you don’t have shore power? You can always use a small 1lb liquid propane heater, such as a Mr Heater. These units are noted as being able to be used indoors, with fresh air. So you will need to keep a window, or two cracked open. There is still a concern for carbon monoxide, so I suggest this as a last resort.

More great info can be found in the Why is My Furnace Blowing Cold Air post.


What happens when your RV Runs our of propane? Due to the many safety features built into your RV heater, it will run cold for about 30 seconds and then shut itself off. Your best bet is to ensure you don’t have a leak and that your propane use makes sense when you last filled the tank. It is also a good idea to have a backup heater, such as an electric space heater, because it is usually in the middle of the night when the propane runs out. Stay Warm!