Tanks & gauges
How long does a 500-gallon propane tank last in the foothills?
A 500-gallon propane tank holds about 400 gallons, which can last a few weeks in a cold snap in a house heated with propane, or many months if propane only runs a water heater and range. To estimate your own, divide the gallons between a fresh fill and your 30% reorder point by the gallons your household burns per day.
Updated · American River Gas office, Newcastle
Step 1: usable gallons before you reorder
Tanks are filled to about 80% so the propane has room to expand, and American River Gas fills to about 86% in winter. You also want to order at about 30%, not at empty. The gallons you actually have to work with are the ones between those two marks.
- 250-gallon tank: about 200 gallons after a fill, 75 at 30%, so about 125 to use.
- 500-gallon tank: about 400 to 430 gallons after a fill, 150 at 30%, so about 250 to 280 to use.
- 1,000-gallon tank: about 800 to 860 gallons after a fill, 300 at 30%, so about 500 to 560 to use.
Step 2: find your daily use
The best number is your own. Take the gallons on a delivery ticket and divide by the days since the delivery before it. Do it separately for a winter fill and a summer fill, because the two seasons are very different in a propane-heated home.
No tickets yet, as in a new house? Read the gauge on the same day each week. A drop of 5 percentage points on a 500-gallon tank is about 25 gallons for that week.
Keep a simple log on the fridge or in your phone: date, gauge reading and the weather that week. After one winter you will know how fast your house burns propane when nights drop below freezing, and you can order before a cold week instead of during it.
Step 3: appliance math as a cross-check
Propane holds about 91,452 Btu per gallon, according to the U.S. Energy Information Administration. Divide an appliance's Btu rating by that number to get gallons per hour while the burner runs.
- 80,000 Btu furnace: about 0.9 gallon per burner-hour.
- 100,000 Btu furnace: about 1.1 gallons per burner-hour.
- 40,000 Btu tank water heater: about 0.44 gallon per burner-hour.
- How many hours a furnace runs depends on insulation, thermostat setting, house size and the weather, which is why tickets beat estimates.
Worked examples for a 500-gallon tank
These are examples of the arithmetic, not predictions for your house. Starting from a winter fill with about 280 usable gallons before the 30% mark:
- A household burning 8 gallons a day in a cold spell reaches 30% in about 5 weeks.
- At 4 gallons a day, it is about 10 weeks.
- At 1 gallon a day, typical of a home where propane runs only a water heater and range, it is most of a year.
What changes the answer in the foothills
Cold nights in the higher towns keep furnaces running longer than in the valley. Older homes with less insulation, a propane pool or spa heater or a shop heater can all add up quickly. A second home that sits empty uses little, but a pilot light and freeze protection still burn some fuel. New appliances change the picture too, so redo the math after adding a fireplace, a tankless water heater or an outdoor kitchen.
Once you know your number, pick the delivery plan that fits it. Keep Full schedules fills from outdoor temperatures and your past use. If you order your own deliveries, check the gauge weekly in winter and call at about 30%. The Budget Plan spreads the year's cost into equal monthly payments.
Questions
Straight answers
How long does a 250-gallon propane tank last?
It has about 125 gallons to use between a fill and the 30% mark, half of a 500-gallon tank. Divide that by your daily use to estimate the weeks.
How long does a 1,000-gallon tank last?
About 500 to 560 usable gallons before reordering, roughly twice a 500-gallon tank at the same rate of use.
How often will I need a delivery in winter?
It depends entirely on your daily use. Work it out from your last winter ticket, or ask the office to look at your delivery history.
Why order at 30% instead of waiting?
Our trucks reach each area on its route day, usually within a week. Ordering at 30% leaves time for that delivery, plus room for storms and holidays. Running out means a required leak check before the gas goes back on.
Should I top off my tank before winter?
It is a good habit if you order your own deliveries. Heading into the cold months with a full tank gives you the most days of reserve if a storm, a power shutoff or a busy holiday week slows things down.
Sources: U.S. Energy Information Administration: British thermal units (Btu), propane = 91,452 Btu per gallon (opens in a new tab) · Propane Education & Research Council: reading your tank gauge (an empty tank must be inspected by a qualified professional) (opens in a new tab) · NFPA 58, Liquefied Petroleum Gas Code (opens in a new tab)
Newcastle yard · since 1966
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