How Much Gas Does A Tankless Water Heater Use

How Much Propane Does a Tankless Water Heater Use?

What is the average amount of propane used by a tankless water heater? When your tankless water heater is connected to a propane fuel source, the answer to this issue is a no-brainer. All of the time, you hear about how tankless water may save you money on your energy bills. That is unavoidable, we cannot dispute it. However, it is always vital to calculate the propane consumption rate. There isn’t any precise information on the question available on the internet. So, what should you do in this situation?

The information in this article will provide you with all of the information you need to calculate the propane consumption of your tankless water heater.

Budgeting propane plans

It is critical to prepare a budget for your propane needs. A smart suggestion for connecting household appliances is to use propane gas as a fuel. Propane has been increasingly popular in recent years due to its ability to burn cleanly and produce sufficient energy. Gas tankless water heaters are primarily powered by either electricity or natural gas. But what kind of gas is it? You may pick from a variety of different types of fuel. We can assist you with a few things. Propane is proving to be the most effective option in this situation.

  1. In most cases, this will lead to a calculation of the overall amount of money spent on propane.
  2. When one understands the rate of consumption, he or she may readily compute the expenditures for a monthly or yearly consumption.
  3. We recommend this for the purpose of your budget and financial planning.
  4. As a result, you will save a tremendous amount of energy.
  5. Regular gas, on the other hand, always generates less heat but burns much more quickly.
  6. The time and money you save will be enormous.

Calculating the propane usage for your tankless water heater

If it had been necessary to compute the amount of propane consumed by your household’s propane-fueled appliances, the computation would have been straightforward. However, calculating the water consumption for the tankless water heater is not a difficult process to complete. It is critical to understand the operation of your tankless water heater before beginning any calculations. First and foremost, determining the quantity of propane required to produce one gallon of water will make the work much easier afterwards.

  • However, there is a catch.
  • It is necessary to get a water softener if the water is a bit hard.
  • You will have to consume more propane in order to keep up with the demand.
  • Instead, it is about taking several crucial factors into account.
  • As a result, it is vital to investigate them.
  • The gallons per minute of a tankless water heater is what determines their efficiency.

In the interim, they are using propane as a source of energy. Some manufacturers will constantly tell you about how to use their products. However, this is not the case for the whole company. As a result, we’ve compiled a list of suggestions. Taking a look at them may provide you with a few ideas.

Propane usage per month on a tankless water heater

In the United States, propane is measured in gallons, although in other parts of the world, it is measured in liters. However, in this article, we will be calculating them in gallons instead. 15 gallons will be plenty for a household of two people. A family of three or four people need 25 gallons of propane each month. The propane consumption of a family of more than 5 people should be 35-40 gallons per year to complete all of their home duties. The estimate is mostly based on the geographic temperature, the water quality, and the availability of tankless water heaters.

Propane usage monthly cost on a tankless water heater

A gallon of propane costs only 2.20 dollars a gallon. As a result, based on the pricing, you can estimate that a family of two will need to spend 33$ a month on food. A family of three to four people will need to spend $55 dollars, while a family of five or more members would need to spend $77 to $88 dollars apiece. The math is straightforward.

Some important FAQ

Making an accurate calculation of your tankless water heater’s overall propane consumption is not a straightforward undertaking. A great deal of thought and calculation goes into the process. I’m not sure if the computation is correct or incorrect. However, information is dispersed over the internet. There is no easy-to-access information that can alleviate your perplexity, and there is no place to turn. We attempted to fix the situation by compiling all of the disparate information. Now, calculating propane gallons and creating a monthly budget for it should not be a major problem any more.

How Much Propane Does a Tankless Water Heater Use in a Year?

Making an accurate calculation of your tankless water heater’s overall propane consumption is not a straightforward endeavor. Many considerations and calculations are made during the process. The computation may be correct or incorrect, but I’m not certain. On the other hand, data is dispersed over the internet. It is impossible to locate easily accessible facts that will alleviate your perplexity. The information that was disseminated over the internet was gathered and used to try to fix the problem.

  • What are the distinctions between propane gas water heaters and natural gas water heaters
  • And When you have a full propane tank, how many showers can you take? In what manner should I determine the amount of propane that a tankless water heater would consume

What You Need To Know About Using Propane vs. Natural Gas Tankless Water Heating

When purchasing a gas tankless water heater, you will have the option of choosing between natural gas or propane gas as the fuel source. Many people believe that natural gas and propane are the same thing, which is not the case. Natural gas and propane, on the other hand, have distinct characteristics that distinguish them from one another. We’ll take care of the pricing of those and other tankless units right here on this page. Natural gas has tended to supplant propane as a fuel of choice because of its abundance and greater BTU levels when used to heat a water heater.

Natural gas is the most preferred fuel because of its cheaper cost, but propane has advantages that make it a more attractive alternative in many scenarios due to its higher efficiency.

It also comes within the category of “alternative fuel” under the Energy Policy Act of 1992, which means that it releases less pollutants into the cosmos than conventional fuels.

Despite its numerous advantages, propane accounts for just approximately 2 percent of total fuel use in the United States.

Looking for Actual Units of Measurement? We have written extensively and provided thorough postings on major tankless manufacturers as well as those that are best “by usage” for your convenience, which you can find here. Take a look at the examples below:

  • A.O. Smith, Noritz, Rinnai, and Rheem are some of the names that come to mind. Choosing the best RV units, the best point of use, the best under sink, the best off grid, and the best for hard water

How To Calculate How Much Propane a Tankless Water Heater Will Use (5 Steps)

You must understand how much propane your tankless water heater will consume in order to guarantee that you have adequate gas on hand and that your budget is appropriate. Naturally, this varies from home to household depending on the type of water heater used and the frequency with which water is used. In five simple stages, we’ll guide you through the process of determining how much propane you’ll need for your water heater. WARNING: THERE IS MATH AHEAD! (You may either read the whole explanation or scroll down to the bottom for the simple solution.)

Step 1: Understand Propane Measurements

Gallons are the unit of measurement for propane. You may have propane tanks delivered to your home, or you can fill up your propane tank at hardware stores and petrol stations on your own time. Recognize the capacity of your propane tank and keep track of how much propane you have on hand at any one moment. There is no short-term expiry date associated with propane, so feel free to stock up for the year (once you finish your calculations).

Step 2: Learn Your Water Heater

British Thermal Units (BTUs) are used to power your tankless propane water heater (BTUs). BTUs are units of measurement for heat, and the heat generated by the water heater burns the propane to heat the water. One gallon of propane is required to produce 90,500 BTUs. Now is the time to learn how many BTUs your specific propane tankless water heater consumes by doing some research. The more the BTUs, the greater the amount of hot water. You will, on the other hand, use up the propane far more quickly.

You will consume around 1.65 gallons of propane every hour if you leave the water running for an hour straight.

Step 3: Analyze Hot Water Usage

The amount of hot water used in your house varies based on the number of people who live there and their individual habits. Gather the entire household to examine your combined hot water use by asking everyone to write down how many showers they took throughout the course of a week and how long each shower lasted. In addition, ask them to keep track of how many times they used the washing machine or dishwasher during the week. Don’t forget to include in hot water from the sink while you’re doing your final calculations.

Otherwise, to estimate water consumption for common equipment, use the formulas below:

  • 1 gallon each 8-minute shower, 36-gallon full tub, 6-16-gallon dishwashing machine, 25-gallon dryer, 1 gallon per sink.

We will assume that each member of a family of four will take a shower on a regular basis. We will also assume that each individual will use the hot water in the sink once a day, unless otherwise stated. At the end of the day, we will assume that they use the energy-efficient dishwasher and laundry machine on a daily basis. According to the preceding estimations, this household consumes 99 gallons of water each day (but let’s round it up to 100 gallons per day for simplicity). Calculating water consumption may be time-consuming, and individuals are not always committed to following a timetable.

If your water heater is equipped with the necessary technology, it can track your water use for you.

Whenever you wish, you may check the app, and you can choose to receive frequent reports in your inbox. This, however, only applies to more recent models that are packed with sophisticated functions.

Step 4: Determine GPM of Water Heater

The gallons per minute (GPM) of water that your water heater can produce vary depending on how hot it is. The increase refers to the temperature of the water when it enters the water heater and the amount of energy required to heat it. According to the Department of Energy, water normally enters the water heater at a temperature of 50 degrees Fahrenheit. The majority of households and professional plumbers set their water heaters at 120 degrees Fahrenheit. This means that the water heater will need to heat the water to around 70° F on average.

However, it will not always be able to produce such amounts of water flow.

GPM will be higher in warmer regions than it will be in colder climes.

Step 5: Do The Math

Sorry for the inconvenience, but we need to conduct some calculations in order to determine how much gas your tankless propane water heater would need. To make things as simple as possible, let’s go over the figures from our water use example once more:

  • 100 gallons of hot water per day
  • 1 BTU warms a gallon of water by 1 degree Fahrenheit
  • Water temperature rises to 70 degrees Fahrenheit at a flow rate of 4.3 gpm
  • The water heater produces 150,000 BTUs per hour
  • 90,500 BTUs equal one gallon of propane.

Even though 4.3 GPM may provide 258 gallons of hot water in an hour, we will only want 100 gallons for our example. Consequently, it will produce the necessary amount of water in 24 minutes. The answer is: (24×4.3)=104 gallons. It is equivalent to the amount of propane consumed in a day if you divide the BTUs generated by the water heater (150,000) by the number of BTUs in one gallon of propane (90,500), then multiply that number by the number of minutes the water heater will be in operation (24 minutes or.4 hours) (.66 gallons).

Round up your propane to ensure that you have enough for all of your requirements.

How Many Hot Showers Can You Get From One Full Propane Tank?

Tankless water heaters deliver limitless hot water, but only for as long as there is enough propane in the tank to feed the heater. You’ve made the decision to purchase a propane tank. Now, how long do you think it will last? Many people like to receive the response in the form of the number of showers. It is dependent on two major variables to provide an answer:

Shower Habits

Prior to anything else, we need to figure out how long you spend in each shower and how much water you use during that time. Approximately 2.1 gallons of water are used per minute by the average showerhead, with the usual shower lasting approximately 8 minutes.

This indicates that you should anticipate to use somewhat more than 16 gallons of water for a single shower. For those who prefer to stand under the hot water and sing (inaudibly) for 15–20 minutes every morning, you may need to increase the amount of gallons used in each shower by a factor of two.

Tank Size

Following that, we must determine the exact size of the propane tank. The majority of households have either a 40 gallon or a 100 gallon tank. The burn rate is the amount of time (measured in hours) it takes to completely deplete a propane tank. You will utilize the information from the metrics that we have already developed to determine the burn rate for the given time period. Make a calculation based on the amount of BTUs necessary to exhaust a pound of propane (90,500), divide it by the amount of BTUs produced by the water heater (150,000), and then multiply that result by the size of the propane tank (40 gallon vs.

See also:  What Is A Condensing Water Heater

Burning rate for a 40-gallon tank is 24 hours per day.

As a general guideline, you should order extra propane when your tank reaches roughly 20% of its capacity.

Don’t be concerned!

Frequently Asked Questions (FAQs)

Find easy solutions to your concerns regarding how much fuel your water heater will consume and how much it will cost to run it in the following section:

How much propane does apropanetankless water heater use?

The majority of households consume around one gallon of propane every day. Approximately one gallon of propane should be more than plenty for a four-person household. This amount should be adjusted according to the number of people living in your house.

How muchgasdoes a tankless gas water heater use?

Natural gas is measured intherms, which is equal to 100,000 British thermal units (BTUs). A household of four using 100 gallons of water per day will use around 395 therms per year or approximately 1.1 therms per day to heat a gas water heater. In March of 2021, the price of natural gas will be $2.62 per thousand cubic feet, which means you will spend $2.88 per day or $1,034.90 per year to heat a gas water tank.

How much propane does a tankless water heater use in a year?

Every year, the average family consumes around 350 gallons of propane. Want to save money on gas by using your water heater at a lower temperature? Start by investing in a correctly sized and energy-efficient water heater, as well as energy-efficient fixtures for your sinks and showers, to assist lower your propane bills. Following that, you should inquire about purchasing propane in quantity, especially during times when propane prices are low. Finally, by taking shorter showers and drying clothing outside on warm days, you may minimize the amount of water you use from your water heater.

How much does it cost to run a propane tankless water heater?

Propane prices vary widely depending on a variety of factors, including the time of year and geographic location. Propane is often less expensive during the warmer months. Aside from that, regional propane rates are lowest in the Midwest, whereas regional propane rates are greatest in New England. When calculating your spending budget, calculate the amount of propane you will consume by the cost of propane in your area.

For example, in March of 2021, the average price of gasoline in the United States was $2.378. A person who consumes 350 gallons of propane per year may expect to pay around $832.30 in gas and electricity costs.

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Tankless or Demand-Type Water Heaters

Known as demand-type water heaters or instantaneous water heaters, tankless water heaters supply hot water only when it is required. They do not generate the standby energy losses typical with storage water heaters, which can result in significant savings in energy costs. You’ll learn the fundamentals of how they function, if a tankless water heater is a good choice for your house, and what factors to consider when choosing the best model for your needs. Take a look at theEnergy Saver 101: Water Heating infographic to determine whether a tankless water heater is the best option for you, and our AskEnergySaver conversation on water heating for additional information on energy-efficient water heating.

How They Work

Tankless water heaters provide fast heating of water without the need for a storage tank. When a hot water faucet is switched on, cold water is sent through a heat exchanger in the unit, where it is heated by either a natural gas burner or an electric element, depending on the device. Consequently, tankless water heaters are able to provide a continuous supply of hot water. The need to wait for a storage tank to fill up with adequate hot water is no longer an issue. The output of a tankless water heater, on the other hand, is limited in terms of flow rate.

  1. Tankless water heaters that run on natural gas have higher flow rates than those that run on electricity.
  2. For example, having a shower while also running the dishwasher at the same time might cause a tankless water heater to reach its maximum capacity quickly.
  3. You may also install separate tankless water heaters for equipment in your house that need a lot of hot water, such as a clothes washer or dishwater.
  4. Demand water heaters are also used in the following other situations:
  • Bathrooms or hot tubs in a remote location
  • Increases the efficiency of household appliances such as dishwashers and laundry washers. Thermoelectric booster for a solar water heating system

Advantages and Disadvantages

Demand water heaters can be 24–34 percent more energy efficient than typical storage tank water heaters in residences that utilize 41 gallons or less of hot water per day on average. For houses that utilize a lot of hot water – around 86 gallons per day – they can be 8 percent to 14 percent more energy efficient than standard models. If you install a demand water heater at each hot water outlet, you may be able to achieve even larger energy savings in some circumstances. A tankless water heater will cost more up front than a normal storage water heater, but they will often live longer and have lower operating and energy expenses, which may more than compensate for their higher purchase price in the long run.

  • They also feature readily changeable parts, which might potentially increase their lifespan by many years.
  • With tankless water heaters, you won’t have to worry about the standby heat losses that come with traditional storage water heaters.
  • When compared to a storage water heater, the removal of standby energy losses might sometimes outweigh the savings from using a tankless water heater.
  • A tankless water heater’s pilot light has a cost associated with it that differs from one type to the next.

Instead of a standing pilot light, look for versions that contain an intermittent ignition device (IID). This mechanism is similar to the spark ignition system used on certain natural gas furnaces, as well as kitchen ranges and ovens, among other things.

Selecting a Demand Water Heater

Before purchasing a demand water heater, you should take the following factors into consideration:

  • Consider the following factors as well when purchasing a demand water heater:

Installation and Maintenance

It is possible to maximize the energy efficiency of your demand water heater with proper installation and maintenance. A variety of elements influence the success of an installation. These considerations include the type of fuel used, the environment, the needs of local construction codes, and safety concerns, particularly with regard to the combustion of gas-fired water heaters. As a result, it is recommended that you use a licensed plumbing and heating professional to install your demand water heater.

  • Request written cost estimates, as well as contact information for references. Check with your local Better Business Bureau to see whether the firm is legitimate. Check to see if the firm will seek a local permit if one is required and if they are familiar with local building rules.

If you’re determined to install your water heater yourself, first speak with the manufacturer about the best way to proceed. The relevant installation and instruction manuals are normally available from the manufacturer. Contact your municipality for information on acquiring a permit (if one is required) and on water heater installation codes in your area. Periodic water heater maintenance may considerably increase the life of your water heater while also reducing the amount of energy it consumes.

Improving Energy Efficiency

Consider implementing some further energy-saving measures once your demand water heater has been properly built and maintained to help reduce your water heating rates. Some energy-saving gadgets and systems are more cost-effective to install in conjunction with a water heater than they are separately.

How Much Propane Does a Tankless Water Heater Use?

Are you one of the homeowners that had a propane tankless hot water system installed in their home? It is reasonable to ask “how much propane does a tankless water heater use?” at this point. Propane burning in a tankless water heater produces an average of 40,000 BTU per hour, which is equivalent to 1.5 gallons of water per day. Propane is a flexible fuel gas for use in the home, and it is well-known for its capacity to reduce energy use. It is important to calculate your propane use since it will assist you in properly understanding and analyzing your total annual energy consumption.

Why You Should Determine Your Propane Usage

The rapid and cost-effective nature of tankless water heaters distinguishes them from conventional gas tanks. Propane is the most energy-efficient fuel gas available on the market today, among the several options available. Typically, the amount of water consumed varies according on the frequency with which it is consumed. It goes without saying that we have diverse families, which means that we have different need for hot water as well. It is critical to keep track of how much water is being consumed by the water heater, especially in big families.

The average cost of propane gas per gallon is between $2.00 and $2.75 dollars.

By keeping track of your propane use habits on a monthly basis, you may sensibly design a budget plan for your propane consumption.

It is vital for you to gather this information so that you can determine your overall propane expenses. As a result, you can exactly manage your propane allowance for your tankless water heater, whether it is monthly or annually.

Calculating Your Propane Consumption

Calculating your propane use does not need the use of any complicated mathematical computations. Don’t let the sheer amount of options overwhelm you. Here’s a quick and easy tip: Always look for the quantity of gallons consumed in a certain period of time. However, in several regions of the world, propane is commonly measured in both liters and gallons; however, I prefer to use the latter because it is much more convenient. Tankless water heaters produce propane in a different way than conventional water heaters.

Some are capable of producing up to 9 gallons per minute.

You may obtain this information by multiplying the BTU rating of your tankless water heater device by 91,452 and dividing the result by 100.

You could be perplexed as to why your monthly propane use has increased significantly despite the fact that you don’t engage in numerous household activities.

Factors That Could Affect Calculation of Propane Consumption

Time allotted for use Inevitably, the more time you spend using your water heater, the more propane it will require to operate. Furthermore, different types of in-home activities need varying amounts of it. What household duties make the most use of your propane tankless system will be revealed over the course of a few hours. For example, you could take a hot shower for up to 10 hours straight or longer, but it would require more propane to keep it as hot as the first 10-minute hot shower in the morning would have required previously.

You must determine how many gallons per minute each of them consumes in order to get an accurate estimate of how much propane is required each month.

  • 0.5 to 1 GPM at the bathroom sink, 2 to 3 GPM at the kitchen faucet
  • Laundry 1.5 to 3.0 GPM
  • Washing Machine 2 to 3 GPM
  • Dishwasher 1.5 to 3 GPM
  • Shower 1.5 gpm to 3 gpm
  • Kitchen Faucet 2 to 3 GPM

I would recommend keeping a record of the instances where you run numerous fixtures at the same time. Keep note of the dates, times, and activities that occur during certain dates and times. If you repeat this process every week, you’ll begin to see a pattern or routine in your propane use. Temperature of the groundwater However, while it is obvious that propane lowers your family’s energy bills by a significant amount, you must also consider the total energy efficiency of propane. The first thing you should look at is where you are going to stay.

  1. If you reside in a frigid northern climate, it will take an excessive amount of time to heat water.
  2. If, for example, the normal groundwater temperature in your location is 52 degrees Fahrenheit, you would want a water heater with a capacity of 5 GPM that can raise the temperature to 53 degrees Fahrenheit in order to have adequately heated household water.
  3. As a result, if you lived in a colder region, you would want a water heater that could withstand the elements.
  4. Water that is hard to drink Investing in a water softener will be necessary if the water coming from the outside source is hard.
  5. The Number of People in the Household The following point was brought up briefly previously in the process of developing a propane consumption budget plan: The use of propane increases according to the size of the family.
  6. In a month, a household of two people will consume around 15 gallons of water, but a family of five or six members will use approximately 40 to 50 gallons of water each month.
  7. This one item alone accounts for a significant portion of the entire quantity of propane consumed.
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Capacity of a Water Heater Tankless water heaters are available in a variety of styles, each with its own water-saving technology.

It will display the amount of propane that is consumed every hour.

A larger gallon capacity means that your model will convert hot water more efficiently than a smaller one.

It simply implies that the more the GPM capacity, the smaller the amount of propane required.

If you check at its features, you’ll see that it has a 7 GPM mechanism that would more than likely fulfill your propane conservation criteria.

According to my previous experience living with my mother, we would only need to pay 33 dollars per month on propane.

When compared to extended families, our propane budget is far less expensive and more cost-effective.

The amount of propane used by each family is determined by how they handle their water heating demands.

The more the number of times we use our water heater on a daily basis, the more propane is consumed. Check the specifications of your heater and apply the formula I’ve supplied to quickly calculate the total amount of energy consumed.


Calculating the total amount of propane you’ve used is less difficult than you would imagine. Propane use may be readily controlled if you have the right knowledge. Always remember to take into account the variables that influence your consumption. It will assist you in making an accurate computation. Units such as the Rinnai RU130iP tankless water heater come highly recommended if you are unsure of what type of tankless water heater to purchase. If you compare it to other types of heaters, it has a superior energy efficiency rating.

Tankless Water Heaters – What You Should Know

Due to the high volume of calls and emails I receive on these units, I am well prepared to deliver my speech. Installing them in a person’s house is something I like doing, however I always include the following disclaimer: They just do not offer hot water in the manner in which we are accustomed to receiving it in the United States. Tankless water heaters, sometimes known as instantaneous water heaters, are becoming increasingly popular. They do an excellent job, and many homes throughout Europe rely on them.

  1. Expulsion of the carbon monoxide-filled exhaust is accomplished by a fan through a flue pipe that, according to most building rules and depending on the unit, must terminate anywhere between one and ten feet away from any building entrance, such as a door or a window.
  2. The units themselves consume a significant amount of gas all at once.
  3. When compared to your 50-gallon gas-fired, tank-type water heater, which consumes around 50,000 BTUs per hour, that’s a significant amount of energy.
  4. Furthermore, because it consumes far more fuel, it requires significantly more fresh air for combustion.
  5. Another 3′′ hole in the side of the home has been created.
  6. This sort of water heater will chug along slowly, burning its 50,000 BTUs a few times each day, and will store the water for when you need it later.
  7. Despite what you may believe, they are not naturally “efficient” in the sense you may expect.

The majority of what we hear about a tankless water heater’s high efficiency has to do with its “seasonal” ratings, and this is best realized when the heater is installed for someone who does not use their hot water very frequently over long periods of time, such as a homeowner who lives in a cold climate.

When it comes to practical application, they promise to provide 6 gallons or more per minute of limitless hot water, but if you look at the material that comes with most typical units, they sort of redefine the term “hot water.” Take a look at these numbers: 90 degrees Fahrenheit climb / 3.2 gallons per minute 77 degrees Fahrenheit climb / 3.7 gallons per minute Temperature increase of 65° F / flow rate of 4.5 gpm 55 degrees Fahrenheit climb / 5.2 gallons per minute 45 degrees Fahrenheit climb / 6.4 gallons per minute The amount by which the temperature of the water will be elevated from the entrance of the heater to the outlet of the heater is referred to as the rise.

  • A 6.4-gallon unit will provide you with an unlimited supply of water that is elevated 45 degrees above the temperature of the water that is being delivered to the unit at a rate of 6.4 gallons per minute from the unit’s reservoir.
  • That’s not a good look at all.
  • This will provide us with water that is 110 degrees.
  • Of course, during the warmer months, this is less of a concern, but it is still something that should not be overlooked.
  • Occasionally, turning on a faucet will not be sufficient to turn on the unit.
  • In order for the process to begin, the flow switch must detect a minimum amount of flowing water, which is typically 0.6 gallons per minute.
  • In order to receive hot water, you may need to turn on the faucet for a greater flow.
  • Probably.
  • Many specialists in the plumbing, heating, and air conditioning (HVAC) industries are increasingly discovering that a mix of tankless and conventional water heaters works well to mitigate the unpredictable behavior of tankless water heaters on their own.
  • Because I am a professional plumber and the owner of Gateway Plumbing and Heating, who is licensed by the Department of Buildings and who is committed to learning about and embracing new technologies in my business, I can confidently declare that I am a fan of tankless water heaters.
  • This type of fuel-burning device is extremely complicated and requires careful consideration before being selected, purchased, installed, or maintained.

You have every right to ask questions before jumping into something. Consider if employing the phrases “efficient” and “endless shower” in the same sentence constitutes a decent first step in the right direction.

How Much Propane Does A Tankless Heater Use

Even if it has been proven several times that tankless water heaters have excellent energy-saving capabilities and operate 1.5 times better than huge tank gas heaters, we still need to ensure that they are refilled at the appropriate time of year. Providing tremendous energy is one thing, but because it contains a lower volume of fuel gas (propane) than a traditional tank water heater, it is critical to understand how much propane is required in order to run our strong tankless water heater at peak performance.

Some Best Tankless Heater Options

Preview Product Rating
1 EcoSmart ECO 18 Electric Tankless Water Heater, 18 KW at 240 Volts with Patented Self Modulating. 3,975 Reviews Buy on Amazon
2 Rheem RTEX-24 24kW 240V Electric Tankless Water Heater, Gray 389 Reviews Buy on Amazon
3 EcoSmart ECO 11 Electric Tankless Water Heater, 13KW at 240 Volts with Patented Self Modulating. 3,449 Reviews Buy on Amazon
4 Rinnai V53DeN Natural Gas Tankless Hot Water Heater, 5.3 GPM 2,003 Reviews Buy on Amazon
5 Rheem 240V Heating Chamber RTEX-13 Residential Tankless Water Heater, GRAY 788 Reviews Buy on Amazon
6 18L Instant Tankless Water Heater, Pevor 36KW Tankless Water Bolier Propane Gas Water Heater. 33 Reviews Buy on Amazon
7 Ecosmart POU 3.5 Point of Use Electric Tankless Water Heater, 3.5KW@120-Volt, 7” x 11” x 3” 727 Reviews Buy on Amazon

Last updated on January 25, 2022 / Affiliate links included / Images sourced from the Amazon Product Advertising API

What are those factors that we have to look upon?

The things we must consider are the number of people who will be in the area where the heater will be installed, the temperature of the region where the heater will be used, and the type of water that will be available in the area (Soft or Hard).

Calculate propane usage tankless water heater

If none of these considerations are a concern, the calculation of propane consumption may be done in a straightforward manner. Because propane in the United States is measured in gallons, we can easily determine the quantity of propane that a propane heater consumes by knowing the heater’s BTU per hour rate. Because one gallon of propane burning produces 92,000 BTU units per hour, we can calculate the amount by dividing the BTU units of the heater by 92000 BTU (the BTU units per hour produced by one gallon of propane burning) and multiplying the result by the number of hours we require the heater to be in operation.

BTU output / 92,000 x the number of hours the heater has been operating


When determining how much propane is being used by a heater, temperature is a critical issue to consider. If the temperature of a particular location is low, it will take considerably longer for the heater to heat the space, consuming more energy provided by the fuel, which in this case is propane. As a result, the lower the temperature of the environment, the greater the amount of propane required to heat the considerably cooler water to a sufficient degree. In comparison to regions with lower average temperatures, the places with higher average temperatures will require less propane in comparison to the places with lower average temperatures.

However, we are unsure of how many times a day or how many months we will utilize the water heater in this location.

Number of People

The amount of people staying at a hotel or any other location where this tankless water heater is in use is also a significant factor in determining how much propane is being used.

The greater the number of users, the greater the amount of propane we use to provide the energy needed to warm the water.

No. of persons Propane requirement (in gallons)
2 15
3-4 25
5 35-40

Here is a table that shows how much propane a family of specific people uses on a monthly basis in gallons of propane. As a result, using the information in this table, one may determine their propane use on a monthly basis. It is sufficient to know the number of members of the household who will be utilizing the water heater in question for this purpose.


A supply of hard water is available in some locations due to the presence of some undissolved salts in the water. Water must be heated in order to become soft, and this requires energy, which comes from the combustion of propane gas, in order to be accomplished. It goes without saying that if a location has soft water, the consumption of propane will be reduced automatically since the water will not need to be heated to the same extent. In addition, while looking at things from the opposite perspective, boiling water is not merely a remedy for softening water.

In order to calculate the quantity of propane used, it is not necessary to take this factor into account, although it can be done in some instances.

Frequently Asked Questions

Q1. Is this formula completely ineffective for calculating the amount of propane consumed by a tankless water heater? It’s not like that at all, this method for the optimal use of a tankless water heater is completely different. In regular usage, when there is fluctuating effect of other parameters such as temperature, hardness, and the number of customers, we are unable to take the formula into consideration. Q2. What makes a tankless water heater superior than a traditional tanked water heater?

Furthermore, because these tankless water heaters have a smaller surface area, they may be installed near water resources that are underutilized, such as faucets in bathrooms and kitchens.

Are these tankless water heaters prohibitively expensive?

It is just the initial installation and wiring of these tanks that is expensive; however, after a while, this initial expense can be offset by the lower energy consumption of the water heaters, which ultimately results in lower fuel costs.


Despite the fact that we have the formula provided above to determine the amount of propane our tankless water heater consumes, there are some additional aspects to consider, such as temperature, the number of customers, hardness, and a variety of other parameters. The solution, we believe, is to compute or learn how much propane is being used by seeing and recording its usage in the home, business, or other location where it is in operation.

How Much Propane Do My Appliances Use?

If you use propane to heat your house, you may be curious in the energy consumption rates of the various appliances that are connected to your system. Depending on the size of your home, you may be utilizing a propane tank that holds 250, 500, or 1000 gallons of propane, respectively. The length of time that your tank will survive between fill-ups will be determined by the sorts of appliances that you have connected to your system and how you use those appliances. The obvious difference between a home of two and a household of nine is that a household of nine uses the shower, the laundry room, and the kitchen at a faster pace.

Britannic Thermal Units (BTUs) are a unit of measurement that specifies the amount of energy required to heat or cool one pound of water by one degree Fahrenheit (one degree Celsius).

Propane produces 91,500 BTUs every gallon of fuel used per hour. To put this into perspective, one BTU is equal to one four-inch hardwood kitchen match that has been entirely consumed. Then there’s the matter of the many appliances that run on propane. Take a look at the following numbers:

  • A pool heater that produces 425,000 BTU/hour or 4 gallons/hour
  • An HVAC furnace that produces 200,000 BTU/hour or 1 gallon/hour
  • A fireplace with ceramic logs that produces 26,000 BTU/hour or 1 gallon every three hours The following are the BTU/hour ratings for gas cooktops and ranges: 65,000 BTU/hour or 5 to 10 Gallons per month
  • Tankless water heater: 40,000 BTU/hour or 1.5 Gallons per day
  • Clothing drier that uses less than one gallon of gas every day (35,500 BTU/hr)
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The numbers listed above will, to some extent, fluctuate depending on how much or how often you use your appliances, as well as the number of people that live in your home, so keep this in mind. Your propane provider can tell you how much propane you use and can assist you in determining how much propane to purchase and how often to acquire it. You may even wish to enroll in your supplier’s budgeting program to ensure that you will always have hot baths and hot meals available when you need them the most.

Get in touch with us right away!

How Much Propane Does A Tankless Water Heater Use? 2021 Complete Guide

Are you interested in learning how much propane a tankless water heater consumes? After all, if your unit is powered by propane fuel, this is a sensible question to ask. The fact that tankless devices are packed with energy-saving qualities is well known to all of us. They outperform typical tank storage devices by a factor of 1.5 times. Yes, these assertions are correct. However, it is necessary to determine the amount of propane that our strong appliance would use. It has been particularly chilly lately, making it difficult for many people to get out of bed in the morning or wash their dishes on such dark days.

  1. They are concerned about spending a significant amount of money on a water heater in order to acquire warm water.
  2. If this is the case, don’t be alarmed.
  3. It is because they are intended to conserve more gas and electricity that they are an excellent alternative for both residential and business establishments.
  4. Additionally, you will obtain an understanding of how much natural gas is consumed by a tankless water heater.

What Is A Tankless Propane Water Heater?

They are an excellent solution for reducing energy use and saving money. It only warms water when you turn on the hot water faucet, rather than boiling water that has been kept in the container before. In addition, they are environmentally friendly and allow you to cut standby heat loss by up to 50%. The ability to obtain an endless amount of hot water without having to pay to keep it deposited is available. The best part is that they offer you with a quick and consistent supply, so there is very little chance of running out of water.

When you are not using it, it does not consume any energy or cost you any money.

It will continue to heat the water until you turn off the fixture. When you turn off the power, the propane gas burner will likewise come to a halt.

How Does A Propane Water Heater Work?

  1. The heater begins to operate as soon as you turn on the faucet. The cold water that enters the device is detected by a drift sensor. Afterwards, it communicates with the control panel, instructing it to make warm water. The fan in the propane-powered device is activated by the control panel, which draws in fresh air from the outside. It is also responsible for opening the fuel valve, which allows propane to enter the building and ignite the burner. In the following step, the heat exchanger collects the heat generated by the flames and transfers it to the tubing system. The integration valve is in charge of regulating the temperature of the heated water that exits the heat exchanger. If the sensor detects that the temperature of the heating water has exceeded or has dropped rapidly below the desired temperature, the control panel will regulate the gasoline valve, floating-regulating valve, and combination valve, among other things. A venting system removes exhaust gas from the machine and transmits combustion air to the tankless version of the machine.

What Are The Types Of Propane Tankless Water Heater?

They are equipped with two heat exchangers. The secondary one is in charge of absorbing any excess heat that is generated before it is released into the ventilation system. It transfers the excess heat to heat incoming water as it flows through the primary heat exchanger, which is located in the boiler. Their energy efficiency rating is 90 percent. This rating is 10 to 15 percentage points greater than that of noncondensing models, depending on the manufacturer.

Noncondensing Tankless Systems

A single heat exchanger provides all of the heating for the system whenever it is needed. The energy efficiency of this heater is 80 percent higher than that of a regular heater, which is just 60 percent more efficient.

How Much Propane Does A Tankless Water Heater Use? Factors To Consider

In order to heat the water as needed, they rely on a single heat exchanger. As opposed to the normal heater, which is just 60 percent energy efficient, it saves you 80 percent on your energy bill.

The Installation Location Of The Device

Tankless machines are small in construction, and they do not require interior air for ignition, unlike traditional machines. As a result, it may be installed in unconventional locations. However, it is preferable to hang it at a location that will save installation costs while also improving performance. As a result, before deploying the system, your plumber should inspect the venting, gas, and water systems. Choosing the proper location will also assist in determining how much natural gas a tankless water heater consumes.

Numbers Of Individuals Live In The House

The number of persons living in the house where the Navien tankless water heater operates is critical when estimating the amount of Navien tankless water heater propane consumption. If there are seven to eight people using the hot water, a larger amount of propane will be necessary to heat the water. A total of 140,000 Btus or 15 gallons of propane will be required if there is only one bathroom in the house that is used by one or two persons. If you have a family of three or four people and have two bathrooms, you will need to spend 190,000 Btus, which is equal to 25 gallons of propane every year.

The Temperature Of The Locality Where You Want To Utilize The Unit

In order to determine how much propane a water heater consumes, it is important to consider the temperature of your area. If you live in a colder climate, you will use your tankless appliance more frequently, which means that your device will consume more of the energy produced by the fuel it is running on. As a result, if the temperature at a given location is lower, the amount of propane required to heat the cold water will be larger. The opposite is true if you reside in a nation with a higher average temperature.

Keep in mind, however, that the weather in your region will not be able to assist you in accurately estimating the quantity of propane your unit will require.

You can only anticipate whether or not consumers will increase or decrease their heater consumption based on the temperature. It is difficult to predict how many times a day or how many months you will rely on your water heater to provide warm water.

Type Of Water In The Neighborhood

Do you live in a region where hard water, which includes undissolved salts, is prevalent? You will need to heat the water in order to soften it, and you will need a substantial quantity of electricity from propane gas to do so. If your location has soft water, your propane consumption will be significantly reduced because it will not be necessary to spend a lot of energy to heat the water. Looking at it from the other perspective, you may use alum to soften water rather than heating it. In order to determine how much propane a tankless water heater consumes, it is not need to take this aspect into consideration, although it can be included in a few instances.

How Much Natural Gas Does A Tankless Water Heater Use?

Every day, they consume around 40,000 BTU, which is equal to 1.5 liters of propane. When it comes to avoiding exceeding the following amount, precision deployment of your gadget is essential. Accomplish you have no idea how to do that? Follow these instructions to ensure a successful installation. If you want the burner on your gadget to function properly, you must connect it to a gas supply line. Propane pressure will be provided by the gas pipes in sufficient quantities. In some cases, you may need to increase the diameter of the gas line to approximately three-fourths of an inch.

  • Furthermore, the condensing equipment is equipped with a larger cooling exhaust and uses inexpensive pipes.
  • As a result, the installation process is simplified because you just need to cut the smallest hole in the wall to complete the installation.
  • As a result, it is essential to install a water softener in order to eliminate scale.
  • In this situation, purchasing a therapy equipment would be the best course of action.

How Many Dollars Do I Have To Spend On Monthly Propane Usage?

The price of a gallon of propane is around $2.20 per gallon. For example, if you have one bathroom and two people living in your home, you will have to invest $33 a month based on the following pricing. For a family of three to four people, you will have to pay $55, on the other hand. Furthermore, if you have more than five people living in your home, you will have to spend between $77 and $90 per month on utilities.

Myths About Tankless Propane Units

In addition, the tank storage devices are inefficient, resulting in the homes frequently running out of hot water. Furthermore, they are only intended to survive for a maximum of 10 years.

It is for this reason that upgrading to a tankless heater is a fantastic choice. Despite the fact that it has a greater initial cost, it may save you more than $200 per year on your energy bills. In three to four years, you will be able to recoup the money that you invested on the improvement.

They Don’t Work With Well Water

Regardless of what type of water supply your home has, the propane appliance will heat the water to the appropriate temperature. Scale building is a problem if you have hard water or if you want more hot water than is currently available. Users receive notifications when their units need to be cleaned since they are up to date. You may also make use of a water softener to reduce scale, so lengthening the time between cleanings and saving money.

They Need Natural Gas

The propane-powered machines have all of the same characteristics as their natural gas-powered counterparts. They operate on a demand basis and only produce hot water when the fixture is turned on. They do not produce the waste of energy and water that tank systems produce. Standby heat loss happens as a result of the tank storage heater constantly heating the water, which means that it consumes energy even when the water fixture is switched off.

They Need Complicated And Expensive Venting

It is necessary to prepare ahead of time when switching from a tank to a tankless water heater, but you may vent the more energy-efficient device through the wall using low-cost PVC pipes. In contrast to tank storage heaters, there is no need to exhaust them via the ceiling with these units. The combustion fan extracts exhaust from the heater in a horizontal direction. Pipe covers and termination points, among other venting solutions, may be relied on to provide adequate ventilation. With a propane heater, you won’t have to spend time worrying about how the venting system will look on your property.

What Are The Reasons To Use A Propane Tankless Heater?

  • Any time you want water, it will provide an infinite supply of precisely hot water
  • And This item has a small footprint, which allows you to save roughly 12 square feet of storage space. Because they are eligible for rebates, they are a cost-effective alternative. The CO2 emissions from these devices are 50 to 60 percent lower than those from electric tank-style devices
  • In this case, they are referred to as immediate or on-demand machines, which signifies that they are meant to operate only when the tap is turned on. In tank storage heaters, this characteristic avoids the standby losses that occur. Power savings of over $150 can be realized by using these units as opposed to regular units.

Conclusion: Determining how much propane is consumed by a tankless water heater is a difficult process to do. This technique necessitates a great deal of deliberation and judgment. However, at the end of the day, there is no way to know if the computation was correct or incorrect. There is a wealth of detailed information available on this subject on the internet. That’s why we’ve put together this comprehensive guide to assist you in calculating propane use for your tankless water heater. We hope that this guide will help you to make sense of things.

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