Knowing an empty propane tank from a full one can save you a bit of nerve and may prevent you from ruining an otherwise well-planned barbeque. Fortunately, there are several different and simple techniques from recognizing if and when your propane tank is nearly empty.
How to tell if your home propane tank is empty?
Here are 4 easy ways to check if your propane tank is running low:
1. Get a gauge
The most precise way is to simply get a propane tank gauge. These can be bought from most local hardware stores and can give you the exact amount of propane you have left in your tank. They come in several different types too but they all work pretty well:
- Analog propane tank scales. These simple scales work like standard luggage scales but take the tank’s weight into consideration. Just hook up your tank, lift it up, and the scales will tell you how much propane you have left.
- Digital propane tank scales. Same principle, from a new century. Digital scales measure your tank’s weight constantly and give you accurate information about how much propane you have left and how much cooking time you’ve got.
- Inline pressure gauges. These are installed between the gas line from the grill and the cut-off valve of the tank. These work by pressure and let you know your tank is full, low or empty.
2. Measure the tank’s weight
The weight of an empty propane tank is usually listed on its handle so you don’t have to wonder “How much does an empty propane tank weigh?” If you look at the tank’s handle you’ll see a few stamped numbers. The WC number is the tank’s water capacity and the TW number is the tank’s weight when empty. So, by knowing the tank’s empty weight you can easily measure how much propane you’ve got left by measuring it.
Most grilling propane tanks weigh 17 pounds (8 kilograms) when empty and can house up to 20 pounds (9 kg) of propane. Still, this may vary with different models so take a look at the handle stamps.
3. Use hot water
This simple method is surprisingly effective – fill a cup with hot water, pour it down one of the tank’s sides, then run your hand down the wet tank and feel for a cold spot. The top of the cold spot is where the current propane level is in your tank.
The reason this trick works is that the liquid propane absorbs heat very well which makes the surface of the tank cool off very quickly when there’s propane on the other side of it.
4. Measure the cooking time
Remember when you were wondering whether you’d need math in your adult life? Well, it’s quite handy indeed. An easy way to always know how much propane you have left in your tank is to calculate how much cook time your tank can provide when full. Here’s what you can do:
Knowing that one gallon (3.8 liters) of propane produces ~92,000 BTUs you can divide that number by the BTUH (BTU’s per hour) of your grill. The end result here will be the number of hours it would take to use up one gallon of propane with your grill.
Now that you know that, multiply that number of hours by the number of gallons in your tank. A standard 20-pound tank (9 kg) holds 4.7 gallons (17.8 liters) of propane.
So, if your grill has 38,000 BTUHs and your tank holds 4.7 gallons of propane, this would give you ~11.4 hours of cook time at maximum grill power.