Best Immersion Water Heaters: With Buyers Guide

Purchasing an immersion water heater may feel overwhelming and difficult, but it's not as challenging as you might think. There are several factors you need to consider to ensure you pick a safe and compatible style that operates efficiently.

But by taking a little time to educate yourself on the different styles of immersion water heaters, and reading our buyer's guide, you'll be able to make a well-informed decision and find the right immersion heater that suits your needs. We'll even show you a few of our favorites to help you get started. 

What is an Immersion Water Heater?

An immersion heater's primary function is to heat the liquid within the container. While there are multiple ways of installation, their purpose remains the same. In addition, they can be used to heat a variety of different substances, such as acids, oils, and salts. This article focuses on immersion heaters that heat water.

An immersion heater is composed of a wire which is encased by both a ceramic covering and another layer of casing called a sheath. The sheath is what radiates the heat to the water within the container. The element is heated with the use of electricity.

There are several different types of immersion water heaters, even though they all have the same general function. Knowing the difference will help you select the type that will best suit your needs. 

Types of Immersion Water Heaters

An immersion water heater is basically a circulation heater (sometimes called inline heater). They are ideal for heating water and freeze protection, among other things. 

Circulation heaters work by allowing liquid or gas to pass through a thermally insulated vessel as it heats the water in which it is surrounded. There are a number of different types of immersion water heaters, the three most common are listed below:

Screw Plug Immersion Heaters

Screw plug immersion heaters are basically the same as flange heaters, except they screw into a threaded opening in the tank wall. Although not as common as flange immersion heaters, many electric water heaters use screw plug heaters to heat the water.

It should be noted that both these immersion heaters are used in other capacities besides water heaters, but nearly all electric water heaters use either the screw plug or flange for heating. 

Over-the-Side Immersion Heaters

Over-the-side immersion heaters are very portable and are frequently called bucket heaters because one of their most common uses it to heat water within a bucket. Some are designed so they attach to the top of a container with a clip, and others can be fully submerged in the water. They typically have an electrical cord and are plugged into an outlet.

Over-the-side heaters have a wide range of uses and are available in a variety of shapes and sizes. Since they are not installed through a tank, they are much more portable than the other heater options. Check out our top three favorites!

Immersion Water Heater Buyers Guide

Although there are a few factors you should consider when choosing an immersion heater, it's actually not as difficult as you might think. Your goal, is to find the right heater for the job, and this ultimately means one that will have a long service life.

Immersion heaters are designed to heat a specific fluid, and the most common is oil or water. So if you purchase a heater that is meant to heat water and you use it for oil, it simply won't last very long. If you are replacing a water heater element, which is an immersion heater, you should read our article that deals specifically with that topic.

There are four factors to should consider when purchasing an immersion heater designed for heating water:

Power Density

Power density, also known as watt density, is another important factor to consider. Watt density refers to the watts per square inch, and it's a critical consideration because you want to prevent the immersion heater from excess heat build-up.

In simple terms, the immersion heater needs to transfer the heat to the water. It's important that the heat leaves the heater and is transferred to the water. If the heat has no where to go (because the water is already hot) the heater will keep getting hotter, and thus shorten it's service life.

This is the same principle why operating an immersion heater outside of water will cause it to burn out. The suggested watt density for an immersion heater designed for portable water is 50 to 75.

Wattage

If you're simply looking for an immersion water heater for home use, you don't need to do any fancy calculations to determine the necessary wattage to heat the water to your desired temperature.

A simple rule of thumb is to purchase the heater with the highest wattage that you can afford for an over-the-side (bucket) immersion heater.

If you're replacing a water heater immersion heating element, then it's a good idea to stay with the same wattage of the one you removed, or check with your manufacturer if you're considering going higher.

Safety

One of the most essential decisions to make when purchasing an immersion water heater is to make sure it comes equipped with safety features.

There are several safety features to consider, one of the most important is the auto shut-off feature. An auto-shut off switch helps prevent fires from starting, or dry burning from occurring. 

The majority of auto shut-off switches are designed to automatically shut off when the liquid being heated gets to the set temperature. Some immersion water heaters even have features that work to maintain the water at a specified temperature. The heater will automatically turn on and off in order to maintain your set temperature range. 

Most immersion over-the-side (bucket) heaters have a guard that surrounds the heating elements. This guard will help prevent the very hot heating elements from coming in direct contact with people or animals.

We also recommend looking for an immersion heater that is UL-Listed and meets all safety standards. 

Best Immersion Water Heaters

Below are our top three choices for over-the-side (bucket) immersion water heaters:

Gesail Electric Immersion (Bucket) Heater

The 1500 watt, 120 volt Gesail Immersion Water Heater can heat water to a near boiling temperature of over 180°F. In fact, it only takes a few minutes to heat 5 gallons of water.

Once the water reaches a temperature between 180° to 194°F, the thermal overload safety switch (located in the middle stainless steel tube) kicks in and the Gesail Immersion Heater will cycle on and off to maintain the water's temperature. This thermostat feature helps prevent the unit from overheating while saving energy.

It also has an auto-shut off safety switch which shuts down the heater if its not immersed in water. This safety feature prevents the Gesail heater from dry burning and catching on fire.

Made from heavy duty 304 stainless steel, it has a safety guard that helps prevent coming in contact with the heating elements. The safety guard design has holes to help reduce the time it takes to transfer the heat to the water.

The Gesail Immersion Water Heater is easy to use. You simply place it in water so that the safety guard is fully submerged (taking care that the black handle and cord are not in the water), and plug it into a grounded outlet. The plug will glow to indicate that the heater is operating. 

Electra SafeHete Immersion Water Heater

The Electra SafeHete Immersion Water Heater is able to heat 1 gallon of water to 90°F in just 10 minutes! The 5-1/2" heater sits at the base of an 11-1/2" rod, and it's small and compact size enables it to fit into tight buckets, pails or sinks. Although it shouldn't be used in plastic containers. Since the base height is only 1-1/4" the Electra SafeHete only needs 1-1/2" of water to operate.

Although the Electra SafeHete is an excellent choice for nearly any use up to 5-gallons, it is especially popular for wet tile saw owners, since the heater can easily fit into the water pan.

It's powered by 1150 watts and runs on 120 volts, and is UL Approved. The heating element is made from incoloy and the outer housing from aluminum. It has an insulated handle to prevent burns while handling.

If the heater isn't submerged in water, the internal protector circuit will shut down the power within a couple of minutes.

It's easy to operate, you simply place the Electra SafeHete Immersion Water Heater within a bucket of water and remove it once the water reaches your desired temperature.

Pong-Dang Fully Submersible Bucket Heater

The Pong-Dang Fully Submersible Immersion Water Heater has 1300 watts of power and runs on 120 volts.  It's a high-end immersion heater designed to heat water, salt water, underground water and solutions.

It has a safety auto-overheat cutoff switch which automatically shuts down the power to prevent the liquid from overheating. The built-in thermostat allows the user to select a desired temperature, then the Pong-Dang heater cycles on and off to maintain that temperature. You can even bring liquid to a boil if you'd like!

The Pong-Dang bucket heater is easy to use. Simply fully submerge the titanium heating element within the liquid, and lay the heating element horizontal or vertical so that the element is fully submerged. Plug the heater into a standard outlet and adjust the thermostat to your desired temperature. 

The adjustable thermostat has a temperature setting range between 30° to 248°F. The titanium heating element connects to the adjustable thermostat with a stainless steel hose, which fully protects the heater while it's under water.