Can I Use A Propane Hot Tub Gas Heater? Yes, But You Need To Know This

Propane hot tub gas heaters make use of propane, a manufactured gas that is stored as a liquid in a tank and becomes gas when it is released for use.

A propane hot tub heater can be used for heating hot tubs since propane heat is a highly efficient and affordable method of heating.

Here are some things you need to know about propane:

  • Propane gas is sometimes referred to as liquefied petroleum gas, LPG for short. Propane gas is a hydrocarbon produced either through natural processes or through crude-oil refining processes.
  • Propane gas is very much like natural gas in that it has no color nor odor. That is, if it is released into the air, you wouldn’t even know it is there. Because of this, to make it noticeable when it is released from its containing vessel, probably due to a leak, an odor is added to the gas during its production process.
  • Propane heating gas is versatile, efficient, and it has no greenhouse emissions, and is approved as a clean fuel by the U.S. government

About propane storage tank

When it comes to using propane gas as a source of energy, whether heat, electrical energy, or other forms of energy, there is always a key necessity that is required aside from the gas itself. This necessity is the tank for storing the gas safely and safely feeding the source that converts it to the desired energy.

Propane tanks can either be installed above or below the ground and they range from small portable sizes to very huge sizes. It can be from 100 gallons capacity to a large capacity of over 1,000 gallons of propane capacity. The larger the container, the longer you can go without having to refill.

Owning and maintaining a propane tank required to run a hot tub can be expensive in some ways, especially during the setup, and probably in the long run. So some persons rent their propane tanks from fuel companies and pay for them on monthly basis. The fuel company does the maintenance on the tank. Owning a personal tank, however, might save you the monthly cost associated with renting one.

But then, be prepared to handle the cost of maintenance that comes with it and possibly more cost that comes with aging and accidents maybe. Worst, when you do not know much about maintaining such a facility as a propane tank, you might end up with a leaking tank, leading to wastage and possible explosion and damage to properties. So one has to be extremely careful with what decision to make as regards propane tanks or natural gas tanks.

Safety tips when using propane hot tub gas heater

Propane, just like other combustible substances, when burnt in an enclosed small space burns incompletely due to a limited amount of oxygen, producing carbon monoxide. Hence it is capable of producing and posing a carbon monoxide hazard which can lead to death when inhaled. Carbon monoxide is odorless, hence it is not noticeable when thoroughly mixed with air.

When inhaled, it mixes and competes with the oxygen in the bloodstream, and deprives some parts of the body of oxygen, the brain especially. Because of this, it is advisable to know the type of propane gas heater you are using if it is the type that is approved for use at homes.

Another safety fact about propane hot tub heaters is that propane gas is a gas that is heavier than air. Because of this, it tends to displace air upwards and fill up a place. Since propane is heavier than air, if there’s a leak, propane will sink to floor level and pool there. If there happens to be an ignition source, such as the pilot light to a water heater, this can pose a very dangerous explosion hazard capable of destroying properties and life.

So, always check for leakage from your propane tank to be on the safe side. This is made easier to some extent because, propane which is an odorless gas, during manufacturing a unique odor is added to it to make it detectable.

How much propane does it take to heat a hot tub?

It would take between one to two gallons of propane to heat an average hot tub. However, the amount of propane gas it takes to heat water in a hot tub will depend on the size of the hot tub, that is the amount of water quantity the hot tub can hold, the more the size or quantity of water in the hot tub, the more the amount of propane needed to heat it.

It also depends on how hot you want the hot tub to be when you use it. The condition of the atmosphere and the weather also slightly affect the amount of propane that would be needed to heat a hot tub since this has an impact on the initial temperature of the water in the tub before heating starts.

The amount of heat needed is measured in the British thermal unit, BTU for short. The British thermal unit (BTU) is a unit for measuring heat. BTU is defined as the amount of heat that is required to raise the temperature of one pound unit of water by one degree Fahrenheit. These days joule (J) is mostly used. BTU is a very similar metric system unit to the calorie, which is defined as the amount of heat required to raise the temperature of one gram unit of water by one degree Celsius.

A gallon of propane will be able to provide you with 91,547 BTUs of heat.

It takes about 8 BTUs to raise the temperature of one gallon of water to one degree. That means to raise the temperature of that same one gallon of water from let’s say by 10 degrees will be 8 BTU multiplied by the temperature increase which is 10. Meaning it will take 80 BTU to raise the temperature of one gallon of water by 10 degrees.

Now, let us estimate the normal temperature of water in the tub to be around 80 degrees Fahrenheit and take the ideal temperature of the hot tub water for soaking as 104 degrees. If your hot tub can hold about 500 gallons of water, to raise the temperature of the water from 80 degrees to 104 degrees would require BTU of the temperature difference between the initial and final temperature multiplied by the BTU required to raise one gallon of water by one degree, and by the number of gallons the hot tub can contain.

That will be (104-80) X 8 BTU X 500 gallons = 96,000 BTU. Now, knowing that about 91,547 BTUs can be provided by a gallon of propane, and considering some possible heat loss. It would take between one to two gallons of propane to heat a hot tub on a normal day, and between two to three gallons to heat it on cold days.

Gas hot tub heater vs electric hot tub heater

Whether to use a gas hot tub heater or an electric hot tub heater comes with there different advantages and disadvantages.

Initial Cost:

The cost of setting up a gas hot tub heater and an electrical hot tub heater is very much different. Gas hot tub heaters require many pieces of equipment and components to set up and run effectively, hence they have a higher initial cost than electrical hot tub heaters. A gas hot tub heater alone will cost about $900-$1200 to purchase. This is excluding the cost of the storage tank to hold the gas, the gas line to safely transport the gas from the tank, or the gas meter to the heater itself.

Coupled with the cost of installation, this additional cost can sometimes exceed the price of the heater itself. Electric hot tub heaters have a very low initial cost when compared to gas heaters. They cost less to purchase and set up than gas heaters considering that you do not have to purchase additional pieces of equipment like gas lines and tanks. The cost of getting on usually falls in the range of $100-$300. This is very much cheaper compared to gas heaters.

But the operating cost of gas heater is far less than that of electric heater. You may be saving up to $30 per month when using gas heater.


Electrical hot tub heaters are protected by a GFCI and several safety components to prevent overheating and electric shock in the water. However, accidents can still happen with 240 volts. Accidents with gas hot tub heaters rarely ever happen, but it is a possibility. If you’re concerned about the safety of gas appliances, it should be about gas leaks and carbon monoxide poisoning.

Installation space:

Installing a gas heater requires more space than an electric heater which can just be tucked underneath a hot tub. A gas heater needs to sit outside in the open air, with access to fresh air and clear sky above for the exhaust.

Heating speed:

Gas hot tub heaters heats faster than electrical heaters. They can add 1-2° per minute, whereas an electric heater may take an hour to add a few degrees.

Maintenance & Repair:

The cost of replacing a heating element in an electric hot tub heater is very cheap compared to that of a gas heater. It cost a few hundred dollars to do it. Replacing a gas heater on the other hand is an expense that can get up to $1000 and even more.

Why is my hot tub not heating up?

If you have observed your hot tub is not heating up even after it has been running for a while. There could be a few reasons for this, which might not commonly mean your hot tub heater is bad or faulty. It could be a common problem such as a dirty filter. It should be the first thing you should check if you are having heating issues instead of going straight to the hot tub heater and probably damaging it in the process.

A dirty uncleansed hot tub filter is usually filled with dirt and debris in between the meshes. This clogs it up and reduces or even stops water flow, in extreme cases, through the hot tub plumbing. It is the continuous water flow that makes it possible for heat to be distributed all around the hot tub.

Try cleaning your hot tub filter first to see if there will be an improvement. So your hot tub filters need to be replaced about once a year, in addition to regular timely cleaning in between. If your heater seems to be lagging, try this first. Take out the filter and rinse it off well.

Another cause of hot tub not heating up can be a blown fuse or tripped circuit if the hot tub heater you are using is an electric one. Check your circuit breaker or GFCI test button to make sure you’re getting electricity, and it is getting to the heater. If after the filter has been cleaned or replaced, and the issue is still there. Then this can be the issue.

If you’ve checked and everything seems to be okay and in good working condition, then you might have a damaged unit of the heater, or the heater itself is bad. A damaged unit like the temperature sensor will not give the right feedback to the heating system, hence it might remain off thinking the hot tub is hot already.

You can inspect the heater yourself and look for damaged wires or anything that looks out of the ordinary. But you will probably need a professional to check it out and fix it.

Signs Your Hot Tub Heater is Failing

  1. No Heat
  2. Tripped Breaker: If you have an electrically heated hot tub, one of the first signs your heater is going bad is that your electrical breaker will trip frequently.
  3. If you’ve gone through the troubleshooting procedures we’ve just outlined and found the issue is either with the heater element or another component of the heater, a replacement will be in your best interest.

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