Over-The-Side Heaters for Industrial Chemical Heating

Over-the-side (OTS) heaters are the most popular type of industrial heater. They can directly address the core challenges of chemical heating:

  • Uniform Heat Distribution
  • Accurate Temperature
  • Safety
  • Simplicity

1. Uniform Heat Distribution

Uniformity in heating is essential for maintaining the viability and quality of chemical mediums. Over-the-side heaters are particularly good at providing uniform heat distribution. Calculations can even include the cold sections of the tank to provide more accurate, uniform heating.

2. Accurate Temperatures

With direct heating, the OTS heater delivers accurate temperatures. It also pairs with thermocouples and intelligent digital controllers. This helps the chemical heating system continuously monitor and adjust the temperature.

3. Safety

Heating chemical requires careful safety considerations. An over-the-side heater can provide great options with careful material selection and accurate temperature ranges (accurate up to 1°). As well, safety devices like fluid-limit and safety shutdown switches can prevent operation in dangerous conditions.

However, an OTS heater isn’t ideal for some types of chemicals. Because of their design (used in open tanks and containers), they aren’t ideal for heating explosive or flammable chemicals. Instead, those chemicals are better off with flange or screw plug heaters that can operate in closed, explosion-proof containers.

4. Simplicity

The over-the-side heater is a simple design. That makes it easy to use, install, and maintain. It simply fits over the side or top of the tank and can be removed to use in other tanks.

Benefits of Over-The-Side heaters for Chemical Heating

In addition to meeting the core challenges of chemical heating, over-the-side heaters also provide several other benefits. These allow them to increase efficiency, quality, and profitability. Some of these advantages include:

Withstand Harsh Conditions

OTS heaters are particularly durable. In part, this is due to their simple design. There are fewer potential failure points and greater reliability. These chemical heaters also use materials and designs that allow them to withstand harsh environmental and chemical conditions.

Chemical mediums can present severe deterioration in different types of metal. We often recommend a fluoropolymer or quartz coating for the sheath material. This protects the immersion heater elements against corrosive fluids and gases.

Indoor & Outdoor Use

Part of the benefit of withstanding harsh conditions is that it makes over-the-side heaters suitable for outdoor use. This means storage tanks and containers don’t have to take up valuable space indoors.

In addition to holding up against the elements, OTS heaters can continue to provide accurate heating in outdoor conditions. They’re also capable of offering freeze protection in cold climates and seasons.

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Space For Other Operations

The design of over-the-side heaters results in an economic use of space. The elements and mounting are all along the side and/or bottom of the tank. This leaves a lot of space for other equipment and fluid processing operations to occur inside the tank.

This reduces the time lost moving fluid to another tank. It also prevents wasted spending on extra storage or processing tanks.


One of the biggest differentiators between OTS and flange heaters is that over-the-side heaters are removable. Most types of immersion heaters are welded into the container, making them a permanent installation.

This gives over-the-side heaters a distinct advantage. You can even skid-mount them for easy moving. This makes it simple and convenient to use one heater for multiple tanks. If you don’t require constant heating in tanks, this is your most economical option.


Like all Wattco heaters, we can customize the materials, design, and power input/output to match your specific requirements. This customization ensures safe, consistent, and predictable operations. You can maximize efficiency in operations with long-lasting equipment built to your specifications.


The same thing that makes over-the-heaters so convenient, also ensure their long lifespan. Since you can easily remove the heater it is especially easy to clean and maintain. You simply take it out of the tank to clean and inspect.

As an additional benefit, removing the heater also means you don’t have to drain the tank for cleaning. This saves time and prevents waste or complication. You may not even have to stop regular operations. This is valuable since in the chemical industry, stopping operations, even short a short period can result in losses of tens of thousands of dollars.

Shop Over-The-Side Heaters for Chemical Heating

Are you ready to learn more about Wattco heaters and which one is right for your application? Visit our industrial heater case studies for more examples and information. Or, reach out to our representatives to find out which piece of Wattco equipment best fits your purpose.

Contact us today for an over-the-side heater quote, or for more information.