Who doesn’t love an awesome RVing hack? We’ve got a great one for you in this post: how to check your propane tank level without a gauge. This tip will save you time and money if you don’t have a gauge (or if your current one has failed, or is inaccurate), and will make it less likely that you’ll run out of propane at the worst possible time. So, let’s get to hacking!
How to Check Your Propane Tank Level Without a Gauge
Checking your propane tank level is important, particularly if you’re not fond of running out of propane in the middle of making dinner or in the middle of a chilly night. Follow the simple steps below (or, for visual learners, watch the video) to check your propane tank level even if you don’t have a gauge on hand:
Fill a Container Full of Hot Tap Water
All you’ll need for this simple RVing hack is your propane tank and a container of hot water. We’re talking hot tap water, not boiling water. As long as your water heater has been on for a little while, the water should be plenty hot enough to do the trick.
Pour Down the Side of Your Propane Tank
Once you have your container of hot water, pour it generously down the side of the propane tank.
Feel the Temperature of the Tank Wall
After you’ve coated the side of the tank with water, run your hand along the side of the tank. Start at the top and move down until you feel the tank’s temperature change.
Pouring hot tap water down the side of a propane tank can help you to determine to what level the tank is filled (or not!) with propane.
Hold your hand on the wall of the tank and run it down the side. The spot where you notice the temperature change from warm to cold will indicate your current propane level. The hot water will heat the side of the tank anywhere the metal isn’t in contact with liquid propane on the inside of the tank. The spot where you notice the temperature change will indicate your current propane level.
Pretty simple, right?
See It In Action, Watch Our Propane Tank Level Check Video
If you’re more of a visual learner, and like to see things rather than read them… here you go:
Why This Propane Tank Level Trick Works
This reaction occurs because the propane inside the tank is cold. VERY cold. The hot water can heat the metal where there’s vapor on the other side of the tank wall (near the top of the propane tank). However, the hot water that flows over the lower part of the tank —the part where liquid propane is in contact with the other side of the metal — is a different story. The temperature of the propane is so intensely cold that it will prevent the metal from warming up.
That dividing line, where the tank temperature transitions from warm to cold, will be a very clear line that you can feel with the palm of your hand. That line between hot and cold is the exact location of the top of the liquid propane inside the tank.
IMPORTANT: Keep in mind that propane tanks can only be filled to about 80% full. So if you find the level to be about 3/4 of the way up the side of the tank, it’s basically full.
This hack gives you only a general idea of where your propane tank level is, but can help you decide if you need a propane refill ASAP or if it can wait.
Check Any Propane Tank Level with the Hot Water Trick
While RVers can use this tip as an RVing hack, it’s not specific to propane tanks in RVs. This hack will work on ANY propane tank you’re using, whether it’s a barbeque propane tank or propane for your home generator.
Can You Install a Gauge on Your Propane Tank?
If you want a more accurate way to keep an eye on your propane tank level, you could install gauges on your tanks.
There are many types of propane tank gauges. If your propane tank doesn’t have a gauge, you can buy one to install on the tank.
Some meters easily screw into any propane tank, while others have magnets that mount to the side or bottom of the tank. Some gauges will even connect to your phone via Bluetooth, alerting you to low propane levels (like this one from GasWatch, or the Mopeka Pro Check Sensor – which is what we use on our new travel trailer because it links to our Victron Cerbo GX and displays the propane level on our Touch 70 display screen).
Propane tank level gauges range in cost from under $15 to $75. Keep in mind that if your RV has more than one tank, you’ll need more than one gauge.
Knowing your propane tank level can be really important, especially since so many RVs rely on propane to cook, heat your rig, or run your refrigerator.
We hope this simple hack will come in handy to keep you or a friend from running out of propane in the middle of an epic boondocking trip or family barbeque.
Free RVing Tips, Tricks, Reviews & Giveaways
As 20-year full-timers, we share everything we’ve learned about RVing over the years. Join our online community to receive a wealth of great RVing knowledge delivered daily to your inbox.
Whether you’re a new RVer or a seasoned full-timer, you’ll love the wide range of RVing topics we cover. Don’t miss a single article or any of our famous Giveaways. Subscribe to our newsletter today!
Jerry Simeone
Monday 16th of June 2025
Hi, I have tried this before and it didn’t seem to work. Maybe it was because it was warm outside. Guessing it’s needs to be colder outside to feel the contrast.
TheRVgeeks
Monday 16th of June 2025
Hi Jerry! It shouldn't matter if it's hot outside, because the propane on the other side of the metal where you're touching is SO cold that it will cool the metal to the touch even in hot weather. We'd suggest using the hottest tap water possible, and pouring a whole gallon down the side of the tank, and then touching it in various places as soon as possible, while the metal is still warm above the propane line where the top of the propane is, and cold below it. The tank should cool quite rapidly where there's propane on the opposite side, and it should be pretty clear where that line is. You can generally feel the difference for about 30 seconds or so, until the upper part of the tank starts to cool back down. Good luck!
Bob Cordy
Wednesday 19th of June 2024
The temperature of the liquid propane inside the tank is the same as the ambient temperature on the outside. To the extent this "hot water" technique works it must be the difference between the thermal conductivity of propane vapor and liquid propane.
Ron Dunn (ND Roughrider)
Sunday 13th of June 2021
They also make temperature sensitive strips that you can mount on the outside of the tank running straight up and down. The strip changes color according to the temperature of the surface it is mounted on so green, dark blue or black would be cold (propane is present), yellow, orange or red (no propane). Colors my vary from strip to strip but you get the idea!
TheRVgeeks
Sunday 13th of June 2021
Thanks for mentioning that, Don! We actually linked to one like that in the article. They’re awesome.
Pat Parker
Sunday 13th of June 2021
Thanks for the great tip…
Larry Snyder
Tuesday 3rd of January 2017
What a great idea thanks for the tip I know it will help a lot of us newbies
Drew Mueller
Friday 20th of October 2017
Hello Peter and John,
I'm having trouble with my 6 cubic foot Norcold fridge while it's running on L.P. It may light ok and maybe even stay on for as much as 30 mins but then the yellow and green lights begin to flash-indicating a problem with the gas flow. If I turn on my water heater in propane mode and then my fridge in lp mode the fridge will operate..until perhaps a few minutes after the water heater has reached operating temp and the flame goes out, then the two lights on the fridge will begin flashing again. Otherwise my fridge works great on electric mode and always stays cold. From what research I've done, it looks like the most likely culprit could be the propane pressure from the regulator. I don't have a manometer but I could by one. I have not seen a through enough video yet to be clear about how to use one. Would you guys be able to help me fix this by either making a video or otherwise directing me what to do?
Linda Heathcoat Wilcox
Friday 13th of January 2017
Love this. I wish I had know about this before dark. I will certainly be using this but need it on the small extender tank , you say it will work on those, hope you show that video too. I have an onboard one with a gauge.
Do you have a video on how to replace the rubber stripping on the slide outs