Collage of six watlow temperature controllers

There are many models and types of Watlow controllers. Some of their common functionalities include controlling temperatures, relative humidity, pH, as well as flow and position of industrial machines and commercial equipment. Explore the integrated controllers with agency-rated safety limits available through leading Watlow distributors, Hi-Watt Inc.

Whether you are looking for a Watlow F4 controller, Watlow PM PLUS, or perhaps comparing single loop controllers to multi loop controllers we can help.

Watlow Temperature and Process Controllers

Watlow temperature controllers range in size and specifications, from a basic single-loop control to a multi-loop, multi-function device.

Most Watlow temperature and process controllers are designed to control one or two loops. Some can control up to four loops.

Compare on/off control modes and PID controllers to determine the best way to monitor and alter your thermal system. You can also choose between an LCD, LED or touch screen display. Here are the form factors available to meet your controller requirements:

  • 1/32 DIN panel mount
  • 1/16 DIN panel mount
  • 1/8 DIN panel mount
  • 1/4 DIN panel mount
  • DIN rail mount

While each controller offers unique features, they all offer the same reliable Watlow quality standards. Review each based on the type of panel and thermal system you have and discuss your options with your Watlow distributor.


From the SMOOTH-TOUCH™ keypad to the EZ-LINK™ mobile app capability, the PM PLUS PID and integrated limit controller is designed for intuitive operations. Enjoy backward compatibility as you send information between your PM PLUS and legacy EZ-ZONE PM controllers to avoid communication errors as you update your facility.

The PM PLUS can only control one limit loop. It does so with a streamlined interface to improve user experience, but not at the expense of customizable controls. It comes complete with alarms and error codes to keep you up-to-date with any thermal system issues.


Control up to four PID loops, complete with data logging options and personal profiles, with the F4T. This highly flexible temperature and process controller uses I/O modules that are field removable for convenient scaling or reconfiguration.

The 4.3-inch graphical touch panel is so easy to use that a user manual is almost unnecessary. Monitor up to 24 channels and create up to 14 alarms to remain in control of your system in a range of harsh operating conditions.


As part of the LEGACY SERIES, the PM LEGACY by Watlow uses a universal input and up to two outputs for a flexible mount package. Over- and under-temperature limit controls, or PID controls, and one limit loop capacity make it a simple, straightforward option for basic applications.

Compare 1/16 DIN and 1/32 DIN panel mount package options to determine the best option for your situation. The menu and control features are more simple than other controllers, but the PM LEGACY is a popular option for simple, reliable thermal control.

Watlow Limit Controllers

Watlow limit controller

Expand your thermal application capabilities with a Watlow limit controller. These controllers are a critical safety feature that helps prevent temperature runaway and over-temperature situations. A Watlow limit controller can be used in multi-loop situations, so they offer a low-cost alternative for a multi-channel facility.

A single loop controller is commonly used for laboratory equipment, furnaces, ovens, boilers, food preparation and more. Choose a double-loop limit controller for plastic injection molding equipment, electronics packaging equipment or any other process that requires multi-channel redundant monitoring.

When you put limits on your thermal system, you keep your entire facility safe. Don’t let an over-temperature or temperature runaway situation damage equipment and products or cause injuries. If you’re ready to improve the safety of your thermal system, consider one of these controller products by Watlow:

  • PM LEGACY Panel Mount Controller
  • PM PLUS PID and Integrated Limit Controller
  • SERIES LF Temperature Limit
  • RM Limit Module

Integrated Multi-Function Controllers

Instead of purchasing multiple controllers and other components, a multi-function controller offers integrated convenience. Reduce the space, assembly time, system complexity and design time of your thermal system with one of these Watlow products.

Select a controller that offers the number of loops you need. Consider safety features, panel styles and configuration style to match your industrial or manufacturing process. Consistent features across an entire line of modular products streamline the setup and integration of controllers around your facility.

Multi-function controllers offer both scalable convenience and a streamlined installation process for your existing setup. Compare these integrated multi-function controllers by Watlow to determine the best device to expand your possibilities:

  • PM PLUS PID and Integrated Limit Controller
  • PM LEGACY Panel Mount Controller
  • F4T Temperature and Process Controller
  • RMA PLUS Remote Access Module

Watlow PID Controllers

Some thermal systems require changing temperatures over time. If you need temperature profiling or ramping, then consider a Watlow PID controller. Standard I/O communication options allow easy integration. A durable design works well in demanding environments, including complex process furnaces and environmental chambers.

Program a specific temperature profile and prepare for accurate thermal controls. A Watlow PID controller works well in many environments and is specifically designed to maintain consistent temperatures with exceptional accuracy. Depending on the controller you choose, you can enjoy up to 40 ramp and soak programs and cascade control.