How Much Propane Does A Tankless Water Heater Use?

Upgraded Home Team
by Upgraded Home Team

No one enjoys the experience of running out of hot water, especially in the middle of a shower. Tankless water heaters are popular alternatives for those who would prefer to avoid the risk of an empty hot water tank.

Several factors work towards the exact amount of propane needed to run a tankless water heater. How many people use it, how frequently hot water is used, the type of water going in, and the ambient temperature are all factors in propane usage.

Listed below is a way to figure out approximately how much propane a tankless water heater uses. It can also factor in with an average price of $2.37 per gallon.

  • 15 gallons of propane per month for two people with a cost of around $35.55 on average per month
  • 25 gallons of propane per month for three to four people with a price of approximately $59.25 per month

Tankless Hot Water vs. A Water Tank

Tankless water heaters provide on-demand hot water. They are a more efficient way to heat water when compared to a traditional hot water tank. The water is heated at the source, and the tankless water heater will only heat as much water as needed for immediate use.

Hot water tanks, by contrast, keep stored hot water at the ready. They are less efficient because some heat is lost while it is stored in the tank. They also need to continuously apply heat to keep hot water ready for when it is required.

Because hot water tanks generally hold on average 30-50 gallons of water, more needs to be heated when the hot water runs out. The tank will have to fill and repeat the process of heating all that water rather than just the amount needed. It is a process that can take an additional 20 to 30 minutes of downtime.

How Does a Tankless Water Heater Work?

When hot water is demanded, water flows into the tankless water heater and goes through a heat exchanger. Hot water is delivered to its destination.

The machine will adjust to provide a constant flow of hot water at a continuous temperature. When the demand is met, it stops heating.

Factors Affecting the Efficiency of a Tankless Water Heater

Several factors affect how efficiently tankless water heaters work when trying to determine how much propane they will need.

How Much Hot Water is Used

The number of hours the tankless hot water is in use will affect how much propane is needed. On average, one gallon of propane can heat up water for a little over two hours.

How many hours hot water is used will mostly depend on how many people use it. The people in the home will want hot water for the following.

  • Showering
  • Cleaning
  • Doing Dishes
  • Washing Clothes

How Hot the Temperature Is

The temperature around the tankless water heater will affect how hard it has to work to heat up water. If the water coming through the tank is very cold, it will have to exert more energy to heat it.

Alternatively, tankless water heaters in warmer climates have less cold water going through them, thus needing less energy to heat the water.

Hard or Soft Water

Hard water is high in salt and mineral content. This type of water generally takes more energy to heat. In addition, the minerals and salts scale inside and around the water heater, creating potential damage and reducing effectiveness.

Soft water has fewer additives in it. It is generally easier to heat and will do less long-term damage to a water heater.

Cost of Propane for a Tankless Water Heater

The actual cost of propane for a tankless water heater will vary. Prices per gallon of propane differ regionally, but the national average is $2.37 per gallon.

Assuming two people use 15 gallons of propane per month, the cost of propane for a tankless water heater will be $35.55. That equals to just under $426 per year.

If there are more than two people using the tankless water heater, the usage will go up. For example, if the usage is 25 gallons of propane per month, the cost of propane for a tankless water heater will be $59.25. That equals to $711 per year.

How to Know How Much Propane You Will Need

What if you’re not an average hot water user? There are a few ways you can track your hot water usage. It will help you better estimate how much propane you will need to fuel your tankless water heater.

Use a Timer

Keep a timer nearby where hot water is used, so you can track how long it is used right at the source. At the end of the month, add up the time used.

You can estimate your hot water usage based on national averages or your own measurements. For example, the average shower uses two gallons of water per minute. You can estimate that a 10-minute shower uses 20 gallons of water.

Track When You Run Out

Keep track of how often you have to refill your propane tank. Multiply that number by the size of your tank, and you will know how much you use over a certain period.

Consult the User Manuals for Appliances

Dishwashers and washing machines are appliances that commonly require hot water. These machines came with user manuals that have information regarding their energy efficiency and water efficiency.

They also might have helpful information on keeping water usage down. If you are concerned about using too much hot water or paying too much for propane, conserving will help.

Minimizing Hot Water Usage

If you are concerned about how much propane your tankless water heater will need, there are ways to reduce your hot water consumption. Reducing your demand for hot water will also reduce the amount of propane needed to heat your water.

Wash Your Hands in Cold Water

Contrary to popular belief, hot water does not help with getting hands clean while washing. The heat needed to kill bacteria is much higher than anyone can handle. Anti-microbial soaps and the action of rubbing hands together do more to get rid of dirt and bacteria than warm water.

Washing your hands in cold water is equally as effective. As a bonus, it can save you energy and money. You will not have to heat the water with propane from your tankless water heater.

Wash Your Laundry in Cold Water

Washing machines use on average 19 gallons of water per a load of laundry. This number will vary based on the type of machine you have and its efficiency rating.

Doing the laundry in cold water not only helps you to save energy and money, but it also helps your clothes to last longer. You will notice the propane lasting longer in the tank.

Take Shorter Showers

Showers, on average, use 2 gallons of water per minute. Every minute that a shower time can be reduced helps to avoid needlessly heating water and paying for propane.

Alternatively, you can install a low-flow showerhead, which reduces the amount of water used per minute, saving money and propane.

Propane Fueled Tankless Water Heater vs. Other Energy Sources

Tankless water heaters are rising in popularity. They are more efficient than traditional tank water heaters, take up less space in the home, and are cheaper to run.

Propane isn’t the only source of fuel available for tankless water heaters. Other models use natural gas, and others use electricity.

Natural Gas Tankless Water Heaters

Natural gas has been rising in popularity over the years due to the fact that it burns cleaner than coal or other energy sources. Propane burns cleaner than natural gas.

With cleaner energy sources, you can feel comfortable that you are reducing your carbon footprint. You are also exposing your family and loved ones to fewer emissions.

Electric Tankless Water Heaters

Electric tankless water heaters are still more efficient than traditional tank water heaters. They operate at a lower efficiency than propane-fueled water heaters. Over time, the cost can add up due to the demand.

Installing a Tankless Water Heater

Tankless water heaters have the benefit of taking up less space than their tank counterparts. They can be placed in non-traditional locations, but they do have to be mounted.

Although you might save money in the long run, the initial cost of installing a tankless water heater can be daunting. The actual price of installing a tankless water heater will vary based on the model and size you choose. You still won’t be paying less than $3,000.

The price can go up even higher if your home needs to be retrofitted to work with the tankless water heater. All gas-fueled tankless water heaters require a vent installed nearby to cope with fumes from burning gas for fuel. It will take propane or a gas company to come in and install a line for the propane gas or a natural gas line.

Upgraded Home Team
Upgraded Home Team

We are a team of passionate homeowners, home improvement pros, and DIY enthusiasts who enjoy sharing home improvement, housekeeping, decorating, and more with other homeowners! Whether you're looking for a step-by-step guide on fixing an appliance or the cost of installing a fence, we've here to help.

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