Furnace Pressure Switch Wiring Diagram: A Comprehensive Guide

When it comes to your furnace, one of the most important components is the pressure switch. This switch is responsible for monitoring the pressure inside your furnace and ensuring that it is running at the appropriate level. If the pressure drops too low or becomes too high, the switch will trigger, shutting down the furnace and preventing potential damage. In this article, we will provide you with a comprehensive guide to furnace pressure switch wiring diagrams.

What is a Furnace Pressure Switch?

A furnace pressure switch is a safety device that monitors the pressure inside your furnace. It is typically located on the blower assembly and is connected to an air tube. When the furnace starts up, the blower motor begins to draw air into the furnace. As the air flows through the furnace, it creates pressure. The pressure switch senses this pressure and sends a signal to the control board, letting it know that the furnace is operating correctly. If the pressure drops too low or becomes too high, the switch will trigger, shutting down the furnace to prevent damage to the unit.

Pressure switches are an essential safety feature in your furnace and need to be wired correctly to work effectively. In the following sections, we will discuss how to wire a furnace pressure switch correctly.

Furnace Pressure Switch Wiring Diagram

A furnace pressure switch wiring diagram can appear daunting, but once you understand what each part does, it becomes more straightforward. There are three essential components of a furnace pressure switch wiring diagram:

  • Pressure switch
  • Control board
  • Vent pipe

The pressure switch and control board are usually in the same location, while the vent pipe is usually located near the furnace’s exhaust. The wiring diagram will show you how to connect these components, so they work in sync with each other.

Step 1: Turn Off The Furnace

The first step to wiring a furnace pressure switch is to turn off the furnace’s power. This will ensure that you do not injure yourself while working on the switch.

Step 2: Locate The Pressure Switch

The pressure switch is usually located on the blower assembly. It is connected to an air tube that runs from the blower assembly to the control board.

Step 3: Disconnect The Wires

Next, you need to disconnect the wires from the pressure switch. You will need to use wire cutters or strippers to remove the wire insulation carefully. Be sure to note which wires are connected to which terminals so that you can reconnect them correctly.

Step 4: Locate The Control Board

The control board is usually located near the furnace’s blower assembly. It is connected to several wires, including those that run to the pressure switch.

Step 5: Connect The Wires

Once you have located the control board, you can begin connecting the wires back together. Each wire will need to be connected to the appropriate terminal on the pressure switch and control board. Be sure to double-check that the wires are connected to the correct terminals. Once you are sure that everything is connected correctly, you can test your furnace to ensure that it is working correctly.

FAQ

What Is A Furnace Pressure Switch?

A furnace pressure switch is a safety device that monitors the pressure inside your furnace. It is typically located on the blower assembly and is connected to an air tube.

How Do You Wire A Furnace Pressure Switch?

Wiring a furnace pressure switch involves disconnecting the wires from the pressure switch, locating the control board, and then reconnecting the wires to the appropriate terminals on both the pressure switch and control board.

Why Is A Furnace Pressure Switch Important?

A furnace pressure switch is essential because it ensures that your furnace is operating at the correct pressure. If the pressure becomes too high or too low, it can cause the furnace to shut down, preventing damage to the unit and keeping your home safe.

What Happens If A Furnace Pressure Switch Fails?

If your furnace pressure switch fails, your furnace may not operate correctly. This can result in a lack of heat or even damage to the unit. If you suspect that your furnace pressure switch has failed, it is essential to contact a professional HVAC technician to diagnose and repair the issue.

How Often Should A Furnace Pressure Switch Be Replaced?

Furnace pressure switches can last many years, but they will eventually wear out over time. It is best to replace your furnace pressure switch when you notice that it is no longer working correctly, or during regular maintenance checks. If you are unsure if your furnace pressure switch needs to be replaced, contact a professional HVAC technician.