How to Choose the Right Heating Element: A Complete Guide to Cartridge, Band, Strip, Silicone and Immersion Heaters

Choosing the right heating element is not always as simple as matching the wattage and voltage.

The type of material you need to heat, the temperature required, the available space, heat-up time and the environment in which the heater will operate can all affect which solution is best for the job.

Whether you are replacing a failed heater, designing a new piece of equipment or improving an existing process, selecting the correct heating element can help improve performance, temperature control and reliability.

At Under Control Instruments, we supply heating solutions for a wide range of industrial and commercial applications. In this guide, we look at the main types of heating elements and how to choose the right one for your application.

What Do You Need to Heat?

The first question to ask is simple:

What exactly needs to be heated?

Different heaters are designed to transfer heat in different ways.

For example:

• A metal block or die may require a cartridge heater.

• A cylindrical barrel or pipe may be better suited to a band heater.

• A flat surface may require a silicone heater mat or strip heater.

• Water, oil or another liquid may require an immersion heater.

• A product requiring non-contact heating may benefit from infrared heating.

Understanding the object, material or medium being heated is the starting point for selecting the correct heater.

1. Cartridge Heaters – For Heating Metal Blocks and Tooling

Cartridge heaters are compact cylindrical heating elements designed to fit inside drilled holes.

They are commonly used for heating:

• Dies and moulds

• Metal blocks

• Packaging machinery

• Plastic processing equipment

• Sealing equipment

• Tooling

• Industrial machinery

A cartridge heater transfers heat directly into the surrounding metal, making it an efficient option where concentrated heating is required.

What to Check When Choosing a Cartridge Heater

Before ordering, check:

• Diameter

• Heated length

• Overall length

• Voltage

• Wattage

• Lead configuration

• Required operating temperature

The fit inside the hole is also important. A poor fit can reduce heat transfer and affect heater performance.

2. Band Heaters – For Cylindrical Surfaces

Band heaters are designed to fit around cylindrical objects.

They are commonly used on:

• Plastic extrusion barrels

• Injection moulding machinery

• Pipes

• Cylindrical tanks

• Processing equipment

The heater wraps around the outside of the component and transfers heat through direct contact.

When selecting a band heater, accurate dimensions are essential. The inside diameter and width need to match the component being heated, while the wattage should be suitable for the required temperature and heat-up time.

3. Strip Heaters/Finned strip heaters – For Flat Surfaces and Air Heating

Strip heaters are versatile heating elements that can be mounted against flat surfaces or used within heating equipment.

Typical applications include:

• Industrial machinery

• Ovens

• Air heating

• Cabinets

• Ducts

• Surface heating

Finned strip heaters are particularly useful for air heating because the fins increase the surface area and improve heat transfer to the surrounding air.

When choosing a strip heater, consider the available mounting space, required heat output and whether the heater is warming a solid surface or moving air.

4. Silicone Heater Mats – For Flexible Surface Heating

Silicone heater mats are thin, flexible heaters designed to provide heat over a surface.

They can be manufactured in different shapes and sizes and are useful where space is limited or where the heater needs to follow the shape of the object being heated.

Common applications include:

• Flat metal plates

• Tanks and vessels

• Electronic equipment

• Laboratory equipment

• Food service equipment

• Frost and condensation prevention

A major advantage of silicone heaters is their flexibility. They can provide controlled, distributed heating without requiring a bulky conventional heating element.

When specifying a silicone heater mat, the important details usually include:

• Length and width

• Shape

• Wattage

• Voltage

• Maximum operating temperature

• Cable position

• Mounting method

• Thermostat or temperature control requirements

5. Immersion Heaters – For Heating Liquids

If you need to heat water, oil or another liquid, an immersion heater may be the most suitable option.

Immersion heaters are commonly used in:

• Water tanks

• Process vessels

• Oil heating systems

• Chemical processes

• Cleaning equipment

• IBC tanks

• Drums

The correct heater will depend on the liquid, tank size and required heating time.

You should also consider whether the liquid is corrosive or contains materials that could affect the heating element. The sheath material is important for ensuring compatibility and long-term reliability.

6. Infrared Heaters – For Fast, Non-Contact Heating

Infrared heaters work differently from conventional contact heaters.

Instead of relying solely on direct contact or heating the surrounding air, infrared energy is directed towards the object or product being heated.

Infrared heating is commonly used for:

• Drying

• Curing

• Paint processes

• Printing

• Food warming

• Industrial production

• Plastics processing

Different infrared wavelengths and heater types are available, including ceramic, quartz and infrared lamps.

The correct choice depends on the material being heated and how quickly the heat needs to be transferred.

How Much Power Do You Need?

Wattage is one of the most important parts of selecting a heating element.

However, choosing the highest wattage available is not always the correct solution.

Too little power may result in slow heat-up times or an inability to maintain the required temperature. Too much power can create excessively high surface temperatures and make accurate control more difficult.

The correct wattage depends on several factors, including:

• Material being heated

• Mass of the object

• Starting temperature

• Required operating temperature

• Required heat-up time

• Heat loss to the surrounding environment

• Insulation

• Number of heating zones

For larger or more complex applications, it may be better to use several heating elements rather than relying on one large heater.

This can improve heat distribution and provide better temperature control.

Why Temperature Control Is Just as Important as the Heating Element

A heating element provides the heat, but the temperature control system determines how accurately that heat is managed.

For a simple application, an on/off thermostat may be sufficient.

For applications requiring greater accuracy and stability, a PID temperature controller may be a better choice.

A complete temperature control system may include:

• Heating element

• Temperature sensor

• Thermocouple or PT100

• Temperature controller

• SSR, relay or contactor

• High-limit safety thermostat

The correct combination depends on the application and the level of control required.

What Information Do You Need Before Ordering a Replacement Heating Element?

If you are replacing an existing heater, try to collect as much information as possible.

Useful information includes:

1. Voltage – for example, 230V or 400V.

2. Wattage – for example, 500W, 1000W or 3000W.

3. Physical dimensions – including diameter, length, width and mounting dimensions.

4. Part number – if available.

5. Application – what equipment the heater is used in.

6. Photographs – particularly useful for identifying older or unmarked parts.

7. Connection details – terminals, leads, plugs or threaded fittings.

A heater that looks similar may not necessarily be electrically or physically compatible.

Checking the full specification before ordering can save time and help avoid fitting the wrong replacement.

Common Signs That a Heating Element May Need Replacing

A failed heater is not always completely obvious.

Common signs include:

• Equipment is taking longer to heat up.

• The required temperature cannot be reached.

• Uneven heating is occurring.

• The heater is tripping electrical protection.

• Visible damage or swelling is present.

• The heater has developed an open circuit.

• The equipment temperature is unstable.

It is also important to remember that a heating problem is not always caused by the heating element itself.

The fault could be related to a thermostat, temperature sensor, controller, relay, wiring or another part of the system.

Testing and correctly identifying the fault before replacing parts can help prevent unnecessary expense.

Need Help Choosing the Right Heating Element?

The correct heating element depends on the application.

There is no single heater that is suitable for every job, and selecting the wrong type can lead to poor performance, uneven heating and reduced component life.

At Under Control Instruments, we supply a wide range of industrial and commercial heating elements, including cartridge heaters, band heaters, strip heaters, silicone heater mats, immersion heaters and infrared heating solutions.

If you are unsure which heater you need, having the dimensions, voltage, wattage and details of the application will make it much easier to identify a suitable solution.

Need help finding a replacement or specifying a new heating element? Contact the Under Control team for technical support and assistance choosing the right product for your application.