How To Test A Furnace Gas Valve

When winter is on the horizon, the last thing you want is a faulty furnace. However, if your furnace isn’t working as it should, the problem could lie with a number of components, including the gas valve. 

While there are some things homeowners can check themselves, the gas valve isn’t one of them. These can be incredibly dangerous without the proper tools and techniques. This article will guide you through how your technician will test your furnace’s gas valve to keep your furnace up and running. 

At Anderson Air, we’re committed to helping you stay warm and comfortable all year long. Keep reading to learn more about your home’s heating system. 

What does the furnace gas valve do and why does it need testing? 

The furnace gas valve is a crucial component of your heating system. Like a traffic officer, it controls when and how much gas flows to your system’s burner to keep your home cozy but not too warm. When the thermostat signals a need for heat, the gas valve opens and allows gas to flow into the burner, which ignites to warm your space. 

When functioning correctly, the valve keeps your furnace operating safely and efficiently. However, if it’s broken or faulty, it can cause issues with heating your home or, worse, potentially release unburned gas into your home.

Professionals test the gas valve to identify faults and nip issues in the bud. 

While it’s good to understand the basics, leave the testing and tinkering to the pros to avoid any safety risks. If you suspect your furnace isn’t working as it should, it’s time to call in the experts at Anderson Air. We’re here to ensure your home stays warm and safe this winter season.

Safety precautions before testing the valve

We recommend leaving the complex things to your technician. However, before your gas valve gets fixed or tested, you can do the following things to help your HVAC technician get set up: 

  1. Turn off the gas supply: Before you do anything else, always make sure the gas supply to the furnace is completely turned off to prevent any gas leaks or explosions.
  2. Disconnect the power: As with any appliance, make sure the power is disconnected before you start working on it to avoid electrical shocks.
  3. Avoid handling wiring: Unless you’re a professional, avoid handling the furnace wires. Incorrect handling can lead to potential damage or even dangerous situations.
  4. Wear protective gear: Always wear gloves and goggles when working on your furnace to avoid any injuries. 

By doing these things, you can help your HVAC technician upon arrival. Leave the actual repair to a team of seasoned professionals like the ones at Anderson Air. 

Testing your gas valve: A guide 

Here’s a quick overview of how one of our professional technicians can test your system for you. Do not attempt to do this on your own. 

  • Locating and Disconnecting the Gas Valve: One of our technicians will begin by locating the gas valve within the furnace. This component is typically near the burner assembly. They will disconnect it from the furnace circuit for safety during the testing process. 
  • Testing for Electrical Continuity: Using a multimeter, the technician will check that there is a path for electrical flow. The multimeter, set to the volt AC setting, is attached to the two connections on the valve. If the multimeter reads between 20 to 28 volts and the valve isn’t opening, the problem is probably in the gas valve itself.
  • Checking the Pressure Switch: Your technician will check the pressure switch, a safety device that ensures the furnace is venting properly before it starts. If this switch is faulty, it might not give the right signal for the gas valve to open.
  • Testing the Gas Pressure: A manometer is used to check the gas pressure. This helps confirm if the right amount of gas is being delivered to the burner when the valve is open. If the pressure is too high or too low, it could indicate a problem with the gas valve or the control mechanism.
  • Assessing the Valve Response Time: The technician will monitor the time it takes for the valve to respond when the furnace is activated. A delayed response might mean your valve is old and needs to be replaced. 
  • Inspecting the Burner: The technician will examine the burner to see if the gas is flowing and igniting properly when the valve opens. Irregular or absent flames can be a sign of a malfunctioning gas valve.
  • Troubleshooting Control Issues: Your technician will also check if there are control issues that could be affecting the gas valve, such as a faulty thermostat or control board. 

By the end of this, your furnace technician will better understand if your valve is working or if it needs to be repaired or replaced. Remember, only a professional should perform these tests to ensure safety and accuracy. At Anderson Air, we have a team of experienced technicians ready to assist you with all your furnace needs.

Common signs of a faulty gas valve 

While it’s hard to check without training and expertise, here are some of the signs of a malfunctioning gas valve. Here are a few signs of a faulty unit: 

  • Thermostat issues: If your thermostat seems unresponsive and your climate doesn’t match your chosen settings, your gas valve could be the issue. A faulty valve can disrupt communication between the thermostat and the furnace, leading to unpredictable heating.
  • Fluctuating temperatures: If you notice hot and cold spots in different rooms or sudden temperature changes, it may indicate that the gas valve is not regulating the gas flow properly.
  • Central heating system not firing up: If your central heating system doesn’t start up at all, your valve might not be allowing gas to flow into the furnace. 
  • Flickering or weak flame: A healthy, functional gas valve should provide a steady gas flow, producing a consistent, strong flame. If the flame is flickering, appears weak, goes out completely or doesn’t ignite, it might suggest a problem with the gas valve.
  • Increased energy bills: Faulty gas valves can lead to inefficient operation of your heating system, causing it to use more energy to produce heat. If you see an unexpected increase in your energy bills, it may be time to check the condition of your furnace’s gas valve.

Remember, it’s always best to contact a professional if you suspect a problem with any components of your heating system. At Anderson Air, we’re dedicated to making sure your home feels like home. 

Call a professional for assistance – Trust Anderson Air. 

While taking a hands-on or DIY approach to home maintenance is commendable, some tasks are best left to the pros. With over 50 years of experience in serving the North Arkansas region, the team at Anderson Air has the experience and expertise needed to get the job done right. 
Don’t let your heating system leave you out in the cold. If you need help with your furnace, call Anderson Air today. We’re your trusted provider of HVAC services.

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