wiring diagram for intertherm electric furnace

Hello readers, welcome to our article on the wiring diagram for the Intertherm electric furnace. In this comprehensive guide, we will provide you with detailed information on how to properly wire your furnace for optimal performance. Whether you are a homeowner or a professional electrician, this article will serve as a valuable resource to ensure a safe and efficient installation. Let’s dive in!

1. Understanding the Basics

Before we delve into the wiring diagram, it is essential to understand the basic components of an Intertherm electric furnace. This knowledge will enable you to comprehend the wiring process more effectively and troubleshoot any issues that may arise. The main components include:

  • Thermostat: The device responsible for controlling the temperature settings.
  • Power Supply: The source of electricity that powers the furnace.
  • Blower Motor: Circulates air throughout the system.
  • Heating Elements: Produces heat within the furnace.
  • Limit Switches: Ensures the furnace operates within safe temperature limits.
  • Transformer: Converts the voltage to the appropriate level for the furnace.

Having a clear understanding of these components will greatly assist in comprehending the wiring diagram.

2. Wiring Diagram for Intertherm Electric Furnace

Now that we have a solid foundation, let’s explore the wiring diagram for the Intertherm electric furnace. Please refer to the table below for a detailed breakdown of the connections:

Wire Color Function Terminal
Red Power Supply R
White Heating Element W
Green Blower Motor G
Yellow Cooling Y
Blue Common C
Orange Reversing Valve O

Ensure that each wire is connected to its designated terminal to avoid any potential malfunctions.

3. The Advantages of Proper Wiring

A properly wired Intertherm electric furnace offers several advantages:

  • Efficient Performance: Correct wiring ensures that the furnace operates at its maximum efficiency, providing optimal heating and cooling for your home.
  • Enhanced Safety: Proper wiring minimizes the risk of electrical faults, reducing the chances of fire hazards or electrical shocks.
  • Easy Troubleshooting: In the event of a malfunction, correctly wired connections make it easier to identify and resolve issues promptly.
  • Extended Lifespan: By following the wiring diagram, you can prevent unnecessary strain on the components, prolonging the lifespan of your Intertherm electric furnace.

4. The Disadvantages of Incorrect Wiring

On the other hand, improper wiring can lead to various disadvantages:

  • Reduced Efficiency: Incorrect connections can cause the furnace to operate below its optimal efficiency, resulting in inadequate heating or cooling.
  • Malfunctioning Components: The wrong wiring can put excessive strain on certain components, leading to premature failure and costly repairs.
  • Fire Hazards: Faulty wiring increases the risk of electrical fires, endangering the safety of your home and loved ones.
  • Voided Warranty: Improper wiring may void the manufacturer’s warranty, leaving you responsible for any repairs or replacements.

5. Alternative Wiring Options

While the provided wiring diagram is the standard configuration for Intertherm electric furnaces, alternative wiring options may be available. It is crucial to consult the manufacturer’s documentation or seek professional advice to determine the appropriate wiring for your specific model.


Here are some frequently asked questions regarding the wiring diagram for Intertherm electric furnaces:

Q: Can I use different wire colors?

A: While the provided wiring diagram specifies certain wire colors, you can use different colors as long as you ensure proper connections.

Q: What if I don’t have a cooling system?

A: If you don’t have a cooling system, you can omit the yellow wire connection as it is dedicated to cooling functionality.

Q: Is it necessary to hire a professional electrician?

A: While it is recommended to seek professional assistance to guarantee a safe and accurate installation, experienced homeowners with electrical knowledge can attempt the wiring themselves.


In conclusion, understanding the wiring diagram for your Intertherm electric furnace is crucial for a successful installation. By following the provided information and consulting the manufacturer’s documentation, you can ensure a safe and efficient operation of your furnace. Remember to prioritize safety and, when in doubt, seek professional assistance. Stay warm and comfortable!