Best Hot Tub Heaters – Updated 2021

hot tub heaters

A Hot tub is supposed to be hot! Yes technically true, as the name itself says so, otherwise it will be just a normal tub or pool of water. Isn’t it!

Conventionally, the hot tubs didn’t use to be hot all the time and were heated on demand, and didn’t have an insulation spa-top either. But modern-day developments have created marvellous heating units with numerous features and benefits.

Let us find out more about them as we scroll down……

Needless to mention, this becomes very potential that you have a hot tub heater which:

  • Brings the water to the perfect temperature.

  • Continues to serve the purpose as long as you require.

  • Get to work whenever needed.

And what if your heater fails when you need it the most!! And this won’t serve your purpose also…. Henceforth, proper guidance to your selection is another thing one can’t ignore.

We have covered the best hot tub heaters of some of the top-notch brands which will never let you down. It is up to you that you choose an electric, gas, or a solar heater for your precious hot tub.

So take a preview of the review by reading below:

Best Hot Tub Water Heaters- A Quick Look

[amazon box=”B007BJYCMK” template=”vertical”]

[amazon box=”B002EL40ZO” template=”vertical”]

[amazon box=”B00IUIBRD8″ template=”vertical”]

Detailed Reviews Of Hot Spa Heaters

1. Electric Heaters

Electric heaters come with a heating element which is packed in a stainless steel tube with union connectors at the end. The tube also has temperature sensors that not only control the temperature but monitor the flow of water too.

These come with a lower price-tag than the gas heaters and the installation is like a breeze. The repair costs and maintenance is also minimal. A small downside is that they may increase the utility bill and take a bit more time to heat water if the outside temperature is cold.

[amazon box=”B007BJYCMK” template=”vertical”]

1. EcoSmart SMART POOL 27 - Electric Tankless Heater

This heater is designed by a well-known brand EcoSmart, electric hot tub heate, which operates at 27kw, is exceptionally compact, and features a size of just 6 x 14 x 17 inches.

Made with the newest flow-sensor technology this tank less system makes use of a digital thermometer and ensures that the hot tub remains heated properly always.

You can set the temperature digitally to the increments of 1-Degree, and just set and forget it. This is compatible with Eco smart remote control and can be used as an alternative to or booster to heat pump.


  • Easy to install to your hot tub.

  • A remarkably compact system.

  • Sets your temperature digitally.

  • Compatible with Eco smart Remote Control.

  • Backed with a 2-year warranty.


  • Consumes significant energy to run.

  • Doesn’t have a waterproof cover.

[amazon box=”B000RP4SIS” template=”vertical”]

2. American Standard 9075120 Safe-T Heater

An electric hot tub heater which is designed with brilliant engineering to keep your hot tub maintain a suitable temperature when in use. This is made to work with any American standard whirlpool tub and you can fill your hot tub with the desired temperature for a nice soaking experience.

This is just easy to install and maintains the perfect temperature for you. This plug and play unit doesn’t require any assembling. This doesn’t heat the water to extreme temperatures and just keeps it warm enough when in use.

Ensure that the pump is turned on, the water is circulating and the jets are running.


  • Maintains a constant temperature.

  • Easy to install.

  • Plug and play operation.

  • Compatible with American standard whirlpool tub.


  • You will need an American standard whirlpool tub.

2. Gas Heaters

Natural or propane gas is supposed to power the gas heaters. These heaters are suitable for free-standing wooden hot tubs, portable spas, and in-ground spas.

Every minute these add 1 to 2 degrees and once you set the spa at a low-resting temperature this heats up rapidly on its own. These are a bit expensive to install as require a gas line connection for gas supply to the unit.

For exhaust purposes the unit needs to sit in the open air.

[amazon box=”B002EL40ZO” template=”vertical”]

3. Hayward H150FDN - Universal H-Series - Natural Gas Model

The Hayward H150FDN is made with cupro nickel for durability and longevity. This supports all conditions, has an aggressive water-flow, and has salt-based water.

The header of the heater comes with a patented polymer design which gives adequate protection to the heater from getting damaged due to erosion. This could happen because of high flow conditions.

The Universal H-Series heater improves in terms of reliability due to its superior hydraulic performance.The combustion chamber prevents any changing weather due to high winds that could affect the heating performance.


  • Environmentally friendly.

  • Easy to read LED controls.

  • Extreme weather can’t effect it.

  • Improved reliability.

  • High-quality hydraulic performance.

  • Emits low NOx.


  • Warranty stands invalid if you install the heater on yourself.

[amazon box=”B07SS4J63T” template=”vertical”]

4. Hayward W3H150FDP- Universal H-Series - Propane Gas Model

Hayward, a brand that has established its name brilliantly over 80 years and are well-known for producing products designed with cutting edge technology.

Even this Hayward Universal H-Series 150,000 BTU Propane Heater delivers premium heating performance which is reliable and provides long-lasting comfort. This has a durable cupro nickel heat exchanger that offers exceptional protection against corrosion and untimely failure that could happen due to unbalanced water chemistry.

This industry-leading hydraulic design minimizes circulation run time to provide major energy savings. Low NOx emissions ensure low environmental impact.


  • Superior hydraulic performance and reliability.

  • Forced draft combustion system.

  • LED digital control panel.

  • Cupro Nickel State-of-the-art Finn Plate Heat Exchanger.

  • Low NOx emissions.

  • Front-panel-only access and intuitive control pad provide easy operation.


  • Great but may not last as long as the others on the list.

3. Solar Heater

There are solar water heaters too and perhaps the most economical of all hot tub water heaters as the complete source of energy is from the sun. For making it run it may require a technical set-up.

Like the electric water heaters this does not raise your utility bills in any way. But these type of heaters are ideal for locations that have ample of sunlight. As lack of sun rays will make their usage worthless.

[amazon box=”B00IUIBRD8″ template=”vertical”]

5. SunHeater S120U - Universal Solar Heater

This pool heating system is the most cost-effective way to warm-up your hot tub, spa, or pool. The SunHeater S120U can be installed with a simple DIY installation.

You can install it on the roof, rack, ground, or fence. This is a patented web design for maximum exposure to the sun’s rays. Proudly manufactured in the United States this has the ability to raise the water temperature 6-10 degrees F.

This makes use of the existing pool pump and keeps the water at the desired temperature.


  • Patented web design.

  • Cost-effective.

  • Simple DIY installation.

  • Universal system suitable for many.

  • Proudly made in the US.


  • Suitable only for places with adequate sunlight.

Ultimate Guide to Buy The Hot Tub Heater

Heater Type

As we have explained above in the write-up too that there are electric, gas, and solar heaters for hot tubs. So, you need to consider every type thoroughly looking into the advantages and disadvantages of both.

Electric heaters though less expensive but are a bit slower than gas heaters. Their set-up is also technical and the units are small in size.

Whereas gas heaters come in propane and natural gas options and do not increase your utility bills too. These could be somewhat larger than others.

hot tub heater types

Solar heaters are perhaps the most inexpensive of all hot tub water heaters as the complete energy is harnessed from the sun. For making it run these may also require a technical set-up. Like the electric water heaters this does not raise your utility bills in any way.


If it is a gas heater then they may emit some exhaust gases and this could be dangerous and unsuitable for you and the environment.

So, when you buy a gas heater ensure that it emits low NOx and wherever you install it there should be adequate ventilation around.

hot tub heater safety tips

It is very essential for the clean air to circulate properly and the harmful fumes (carbon monoxide) will stay away.

If it is an electrical heater then ensure that the set-up is proper to avoid any electric shocks or heater failures.


The amount of water which needs to be heated in your hot tub, will dictate the decision of the heater you select.Once you are clear about the specifications, then you will never go wrong in selecting one.


For this you can check some honest customer reviews before you finalise your purchase. We have mentioned some of the best brands available and you can select as per your requirement parameters.

Even the experts recommend that quality should never be compromised.


Get a heater that shows compatibility with your hot tub in every way. Generic units need to be avoided as they may work one day and break the other day.

The manufacturer instructions should be followed completely as most of the models come with capacity details and the amount of water they will be able to tackle.


Any product you invest in should be checked for its material first. For durability, longevity, and smooth service for years a heater made with superior quality material will always remain reliable and useful.


There could be real difficulties in installing some complicated units and this could make the process tedious. Go for a heater with simple installation process and this will not only give you peace of mind but ease down your work too.

The Final Verdict

You should take a complete note of specifications of the unit before you select your hot tub heater.

Just go with the type of heater that suits your surroundings, hot tub size, and budget too. Remember that one good investment will leave with more years of satiating experience. Pick the one that meets your heating needs in the best possible way.

Have a fabulous soaking experience!!

Frequently Asked Questions

Q 1. Which gas heater should I choose to use in my hot tub?

Ans: This depends on the place where your hot tub is located, and if it is outdoors then a natural gas heater is recommended. The underlying reason is that it is quick, efficient, and economical to use.The heat consistency is also maintained perfectly with this. If you want for indoor use then electric heaters are a good option though.

Q 2. What could be the cause of slow heating?

Ans: If your heater is heating slowly then there could be the undermentioned reasons for this:

– The hardware of the heater is old and worn-out (regular servicing of the tub is recommended).

– Ambient temperature contradicts your heater.

Expert tip: If you keep your hot tub cover then it will quicken the heating process.

Q 3. How can I make my hot tub heater maintain its consistency even in windy season?

Ans: If there is sufficient plantation of trees or bushes around the hot tub then they will certainly work great to keep your heater maintain its heating consistency. Clean and green surroundings will surely help in breaking the wind effects.

Q 4. How does a water heater work?

Ans: Firstly, the water goes to the pump and then is transferred to the filter for cleaning purposes.

Q 5. How can I install my water tub heater?

Ans: Prior to installation of water heater, you need to ensure that the water is drained properly. Also check that the hot tub has its power off. Some steps are mentioned below:

– The power line that connects the tub to the heater should be disconnected.

– The couplings should be removed and then the heater should be taken out.

– Make the proper installation set-up and put everything back.

– Just connect the power line and the hot tub is ready for use.