How To Tell if Your Propane Tank Is Empty

Date: August 22, 2022

Checking Your Grill’s Propane Supply

grill tank tennesseeAbout the fastest way to throw a damper on your backyard barbecue is having your propane cylinder run out of fuel—right when those fat and juicy steaks have just started to cook.

Since most propane portable cylinders don’t come with a built-in gauge, you need another way to figure out how much fuel is left in your tank. You obviously don’t want to wait until your grill shuts off to tell you that your propane tank is empty. (That’s why it’s best to always have a back-up propane cylinder on hand—just in case.)

3 Simple Methods to Measure Your Cylinder Level

  1. Use water. You can determine the approximate level of propane in a tank by using a little bit of water. Here’s how:
    • Fill a small bucket with hot tap water.
    • Pour the water down the side of the tank.
    • Run your hand along the side of the tank and feel for a cool spot.

    The top of the cool spot is the fill level of the tank – it’s cool because liquid propane inside the tank is absorbing the heat from the water, which makes the metal wall of the tank cool to the touch.

  2. Weigh the tank. Most propane grill tanks come with two numbers stamped on the handle – the water capacity (“WC”) and Tare Weight (TW – the weight of the tank when it’s empty). Most grilling tanks weigh about 17 pounds when empty. To measure how many pounds of propane are left in your tank, simply weigh it on a scale and subtract the TW number. For example, if a tank weighing 27 pounds has a TW of 17 pounds, there’s about 10 pounds of gas left—or about 2.5 gallons.
  3. Use an external gauge. External propane tank gauges come in several different forms
    • inline pressure gauges install between the gas line from the grill and the cut-off valve on the tank, measuring pressures to determine how full the tank is.
    • analog propane scales look like luggage scales and are pre-set to take your tank’s TW into account.
    • digital propane tank scales provide a digital readout of remaining cook time and gas fill percentage. Some even come with smartphone apps.

    Pick the device that you’re most comfortable with and give it a try!

Understand the Safety Behind the 80/20 Rule

When you take your portable 20-lb propane tank to a refill station or tank exchange, you should get four gallons (or 17 pounds of propane; propane weighs 4.25 pounds per gallon). For safety reasons, the propane cylinder should only be filled to 80% of its maximum capacity. Leaving it 20% empty leaves room for the LP gas to expand, which it will do when the temperature rises. A propane cylinder illegally filled to 100% capacity could burst. This same 80/20 rule also applies to your home heating propane tank.

Storage and Transportation of Propane Cylinders

Please review these safety handling tips for your portable propane cylinders.

  • ALWAYS store or place a propane cylinder outdoors and in an open area, and not in a basement, garage, shed or tent.
  • ALWAYS keep cylinders away from a stove, fireplace, or other heat source. This is also why you should not store a spare cylinder under or near your barbecue grill.
  • ALWAYS stay aware when you are handling cylinders. You don’t want anyone smoking near it and make sure your cylinder does not come into contact with ignition sources such as flames or spark-producing electrical tools.
  • ALWAYS leave the care and repair of a cylinder in the hands of a skilled propane professional. You should not make any attempt to modify or repair valves, regulators, or other cylinder or appliance parts.

That’s because propane cylinders incorporate special components such as valves, connectors, and other parts to keep them safe for use with grills and other propane appliances. Damage to any component can cause a gas leak. Don’t risk it! Instead, contact a qualified propane service provider for assistance.

We want to make sure you know how to approach propane safety in and around your home or business, no matter how you’re using propane. We encourage you to go here to review propane safety and operation tips, courtesy of the Propane Education and Research Council.