how to check furnace circuit breaker


Furnace Circuit Breaker: A Guide to Checking and Troubleshooting


A furnace is an essential component of a heating and cooling system in many homes. It provides warmth during cold seasons, ensuring a comfortable living environment. However, like any electrical appliance, furnaces can encounter problems from time to time. One common issue is a tripped circuit breaker. When this happens, it disrupts the flow of electricity to the furnace, causing it to shut down. In this article, we will guide you on how to check your furnace circuit breaker and troubleshoot any issues that may arise.

Understanding the Furnace Circuit Breaker

The furnace circuit breaker is an electrical safety device installed in the main circuit panel of your home. Its primary function is to protect the furnace and other electrical components from overloading and potentially causing a fire. When the electrical current exceeds the breaker's rated limit, it automatically trips, cutting off the power supply to the furnace. This prevents electrical damage and ensures safety.

The circuit breaker consists of a switch that can be manually flipped to reset it once it has tripped. Identifying and troubleshooting a tripped circuit breaker is crucial to ensure the uninterrupted functioning of your furnace.

Signs of a Tripped Circuit Breaker

1. Complete Shutdown: One of the most apparent signs of a tripped circuit breaker is a complete shutdown of your furnace. If your furnace suddenly stops working, it could be indicative of a tripped breaker.

2. Lack of Heat: Another sign is the absence of warm air flowing from your vents. When the circuit breaker trips, it cuts off power to the furnace, resulting in a lack of heating.

3. Disrupted Thermostat: A tripped circuit breaker can also cause the thermostat to lose power, resulting in an unresponsive or blank display. In such cases, the furnace may appear to be functioning correctly, but it won't generate any heat.

4. Frequent Tripping: If your circuit breaker frequently trips when the furnace is in use, it may indicate an underlying electrical problem. In such cases, troubleshooting becomes crucial to identify and resolve the issue.

How to Check the Furnace Circuit Breaker

Before proceeding with the troubleshooting steps, ensure your safety by following these preliminary precautions:

1. Turn Off the Power: Before inspecting or working on any electrical components, turn off the power supply to your furnace by switching off the circuit breaker dedicated to it in the main electrical panel.

2. Use Safety Equipment: Always wear appropriate safety gear, including gloves and safety goggles, when dealing with electrical systems.

Now, let's dive into the step-by-step process of checking your furnace circuit breaker:

Step 1: Locate the Main Electrical Panel

The first step is to locate the main electrical panel in your house. It is typically located in the basement, utility room, garage, or outside your home. The panel will have a door that you can open to access the breakers inside.

Step 2: Identify the Furnace Circuit Breaker

Once you have located the main electrical panel, look for the breaker labeled as 'Furnace' or 'HVAC.' Circuit breakers are usually labeled, making it easier to identify the one associated with your furnace. If you cannot find any labels, consult your furnace's user manual or contact a professional for assistance.

Step 3: Inspect the Breaker

To inspect the breaker, you need to determine its current position. A tripped breaker will be in the middle position, between the 'On' and 'Off' positions. It may also be slightly pushed towards the 'Off' position. A breaker in the 'Off' position might not be tripped; instead, it may have been manually turned off.

Step 4: Reset the Breaker

To reset the breaker, firmly push it to the 'Off' position and then back to the 'On' position. This will help ensure that the breaker is correctly seated and can restore power to the furnace. If you encounter resistance or the breaker immediately trips again, it indicates a potential fault within the furnace or the electrical circuit, which will require professional attention.

Troubleshooting Potential Issues

In some cases, resetting the circuit breaker doesn't resolve the problem. Here are a few potential issues and troubleshooting steps to consider:

1. Overloaded Circuit:

If the breaker consistently trips immediately after resetting it, it may indicate an overloaded circuit. This means that the electrical load exceeds the breaker's capacity. To rectify this issue, try the following:

- Reduce the load: Unplug any unnecessary electrical devices connected to the same circuit as the furnace.

- Spread the load: Distribute heavy electrical loads across multiple circuits by using extension cords or power outlets dedicated to other breakers.

2. Short Circuit:

A short circuit occurs when a hot wire comes into contact with a neutral wire. Resetting the breaker will likely lead to immediate tripping. If you suspect a short circuit, here's what you can do:

- Inspect the wiring: Visually inspect the electrical wires connected to the furnace for any visible signs of damage or loose connections. Ensure they are well-insulated and securely connected.

- Seek professional assistance: If you are uncertain or uncomfortable with performing electrical troubleshooting, contact a licensed electrician to diagnose and fix the issue.

When to Consult a Professional

While checking the furnace circuit breaker can often resolve the issue, there are situations when it is best to seek professional assistance. Consider contacting a licensed HVAC technician or electrician in the following scenarios:

- The breaker continues to trip after resetting.

- You notice any signs of electrical damage or loose connections.

- You have limited knowledge or experience in HVAC systems or electrical work.

- The furnace is not working even after the breaker appears to be functioning correctly.


A tripped circuit breaker can interrupt the functioning of your furnace, leaving you without heat during cold periods. Learning how to check and troubleshoot the furnace circuit breaker is essential for every homeowner. By following the steps outlined in this guide, you can identify a tripped breaker, reset it if needed, and potentially resolve the issue, restoring warmth to your home. Remember to prioritize safety throughout the process, and always consult a professional if you encounter any difficulties or uncertainties.


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