Posted: December 2, 2024

Why Isn’t My Propane Tank 100% Full After a Delivery?

There’s a propane safety precaution called the 80/20 Fill Rule.

At Koppy’s Propane, there are some questions we get quite often from our customers. Our friendly team members are always happy to answer any inquiry you have about how we handle and deliver your fuel. Even so, we wanted to take a moment to ask one of the standard questions we hear every day: Why does a propane tank gauge read 80% instead of 100% after a propane delivery?

We’ll answer that in a minute, but first, let’s discuss how you can check your propane tank levels.

How do you read a propane tank gauge?

You’ll typically find your propane tank gauge under a dome on top of the tank. It looks a lot like a car’s speedometer, showing numbers from 5 to 95. These numbers indicate the percentage of the tank that’s full, not the exact gallon count. So, if your 250-gallon propane tank gauge reads 50, you’ve got around 125 gallons of fuel left.

Why might the reading on a gauge change when you aren’t using propane?

Propane’s volume expands and contracts with changes in temperature, just like water’s volume does. But here’s the difference: propane’s volume increases 17 times more than water’s with the same temperature rise. Your propane tank’s gauge has a float to show how much space the fuel takes up. This means outdoor temperatures can mess with the gauge reading. So, if we fill a tank to 80% on a warm day and the temperature drops a lot at night, the gauge might show less than 80%, even though the amount of propane hasn’t changed.

Why do we only fill a propane tank to 80%

Let’s talk about why your aboveground propane tank’s gauge never hits 100%, even after a delivery. It’s all about the “80/20 Fill Rule” that responsible propane companies follow. We intentionally leave 20% of the tank empty to allow for propane expansion, an essential safety measure to avoid pressure buildup on hot days.

Incidentally, underground tanks can handle the heat a bit better because the ground insulates them from temperature fluctuations. They can be filled a bit more.

And don’t worry; you’re only charged for the propane that goes into your tank, not the empty space.

Koppy’s Propane is the top propane provider in Cumberland County.

If you want the safest, most dependable home propane delivery in Central and Southeast Pennsylvania, look no further than Koppy’s Propane. For 80+ years, we’ve delivered top-quality fuel and total peace of mind to our customers. You can rest easy, knowing you’ll always have the propane you need. That’s because we offer a FREE automatic delivery schedule. How does it work?

Our system tracks your home’s typical fuel usage based on the outside temperature. We’ll automatically deliver fuel when your tank is 25-30% full. It means no more run-outs, calls for delivery, or waiting for the truck to arrive.

At Koppy’s Propane, we’re passionate about ensuring your home comfort. Join our family of satisfied customers today.