How Much Propane Does A Tankless Water Heater Use?

How much propane does a tankless water heater consume? Well, when your tankless water heater is hooked up with propane fueling this question is logical. You are constantly hearing about the tankless water saving energy all the time. Yes, we cannot deny that. But still calculating the propane usage is always important. There is no specific information about the question online.

So, what to do about the situation? Quite simply, we can help. The content will highlight all the necessary information about calculating propane use of your tankless water heater. Let's just move on with the reading.

Camplux 5L 1.32 GPM Outdoor Portable Propane Tankless Water Heater
  • Budgeting propane plans

Budgeting the propane plan is important. Using propane gas to hook up home appliances is a good idea. Featuring clean burning and proper energy production, propane has become quite popular in recent years. Gas tankless water heaters mainly operate using either electricity or gas. But what type of gas? There are plenty of fueling gas to choose from.

Camplux 10L Outdoor 2.64 GPM Digital Display Portable Propane Gas Tankless Water Heater

We can help you with some. Propane is becoming the best choice in this case. Now when you just want to use propane to fuel the tankless water heater, you need to calculate the usage. Generally, this will lead one to calculate the total spending over propane. Budgeting for propane requires proper calculation.

When one gets to know the usage rate, he can easily calculate the spending’s for monthly or annual usage. So, first of all when one asks why should we know about the usage rate for the heater? We say for the sake of your budget and saving up money.

Instant Propane Water Heater

When propane is used for fueling the water heater, it emits 60% less greenhouse gas than the regular gas. So, it will save you a ton of energy. You will get proper heating using the gas. On the other hand, regular gas always produces less heat but burns a lot. Just 1 gallon of propane can replace 3 to 4 gallons of gas. Saves you a ton of energy and cash. But still calculating the usage rate also sums up all your requirement monthly.

  • Calculating the propane usage for your tankless water heater

If it were to calculate the usage for your household propane-fueled appliances, the calculation would have been easy. But calculating the usage for the tankless water heater is also not a very hard task at hand. Before calculating, understanding the function of your tankless water heater is important. First of all, calculating the amount of propane burned for producing 1-gallon water will make the job easier.

Marey GA10LP Power 10L 3.1 GPM Propane Gas Tankless Water Heater

It is the gallons per month that you need to collect. But here is a catch. The burning or energy production highly depends on geographical temperature. If the water is a little hard, one needs to get a water softener. That is also a problem. You will need to burn more propane. So, it is not just about the gallons per minute and the rate of propane to heat that much water. Rather it is about making some important consideration.

Rinnai V Series HE Tankless Hot Water Heater

The temperature in different regions are not the same. So, checking them out is necessary.  Also, the support of your tankless water heater and gallons per minute is also a consideration.

The tankless water heater is determined by their gallons per minute. Some heater model produces 5 gallons per minute and some model can even pull off 9 gallons per minute. In the meantime, they use propane as fuel.

Some manufacturer always informs you about the usage. But not all the manufacturer. So, we have come up with a list. Checking them out may give you an idea or two.

Camplux 10L Outdoor 2.64 GPM Digital Display Portable Propane Gas Tankless Water Heater2
  • Propane usage per month on a tankless water heater

In the US region, they calculate propane as gallons and on the other areas they use liter. But in this content, we are going to calculate them on gallons.

For a family of 2, 15 gallons will do just fine.

For a family of 3 or 4 needs 25 gallons of propane monthly.

A family of more than 5 members should need 35-40 gallons of propane to do all their household chores.

The calculation mainly depends on the geographical temperature, water quality, and tankless water heater support. Check out the features of your tankless water heater first.

Eccotemp i12-LP water heater, 4 GPM, Black
  • Propane usage monthly cost on a tankless water heater 

A gallon of propane just costs 2.20$ each. So based on the price, you can say that you will need to spend 33$ monthly for a family of two. A family consisting of 3 to 4 members will need to spend $55 dollars, a family consisting of more than 5 members need to spend $77 to $88 each. The calculation is quite easy.

Some important FAQ

How to adjust temperature on rinnai tankless water heater?

Is propane safe to use on my tankless water heater?


Calculating the total usage of propane on your tankless water heater is not a simple task. The process includes a lot of consideration and calculation. Not sure the calculation is right or wrong. But information is scattered around the web. Finding easy to access information that will ease your confusion is nowhere to be found. We tried to resolve the problem by gathering all of the scattered info. Now calculating propane gallons and budgeting for it monthly should not be that of a hassle.

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