How To Check Gas Valve On Furnace? A Comprehensive Analysis

how to check gas valve on furnace


As a homeowner, checking your furnace gas valve is critical for safety and correct heating. 

Here, we’ll provide the steps and tools you need.

First off, what does the gas valve do? It regulates the flow of natural gas to the furnace burners, which heat your home. If it’s faulty, it can cause pressure problems during startup and beyond.

  1. First, turn off the furnace power from the control board or thermostat.
  2.  Next, locate the gas valve terminals and use a multimeter to test for 24 volts on each terminal.
  3. To check internal valve operations with power on, listen for clicking noises. This indicates the solenoid coil opening and closing as programmed.
  4. Also, use a manometer to measure pressure between input/output ports.

If there are issues with readings or no flame sensor signal after checking leads; it may be a bad gas valve.

Repairs or replacements must only be done by an HVAC technician, so don’t try fixing yourself if you’re not equipped.

To sum up, understanding furnaces and how to check components like gas valves can help detect issues before they become serious. Safety first!

Basics Of Gas Furnace

To get started with your gas furnace, it is essential to understand the basics of a gas furnace.

 With the title “How to check gas valve on the furnace,” this article aims to guide you on the steps you need to take to check the gas valve on your furnace. 

To do this, we will first look at the gas furnace components, where you will get to know all the different parts that make up your furnace. 

We will then explore the understanding of the gas valve, where you will learn how to check and fix gas valve-related problems in your furnace.

Gas Furnace Components.

Gas furnaces are a popular choice for heating homes and commercial spaces. They have various components that work together to provide warm air and maintain temperature during cold weather.

 Let’s take a look at the different parts of a gas furnace!

  1. Gas Valves control the flow of gas into the burner assembly.
  2. Burners produce flames by igniting this gas.
  3. Heat exchangers transfer heat from combustion to warm air circulated through ductwork.
  4. Blower motors power the fan that pushes heated air out of the furnace and into the home.
  5. Control boards monitor and manage the functions of the furnace components.
  6. Apart from these, gas furnaces also have thermostats. This lets users set their desired temperature and adjusts furnace operation accordingly. 

The size and capacity of each component depend on the type and design of the furnace.

To increase gas furnace efficiency, it is recommended to replace air filters regularly and get maintenance checks done by professionals. Avoid setting high-temperature ranges as it can damage parts or cause carbon monoxide leaks. By following these tips, homeowners can ensure their furnace has a long life span while keeping their homes warm and comfortable during cold seasons. 

Get to know your gas valve intimately – your furnace’s fate depends on it!

Understanding the Gas Valve.

When it comes to furnaces, the gas valve is a must. It opens or closes depending on signals from the thermostat. Knowing how the gas valve acts is key for a safe, efficient furnace.

Different valves exist, but each with its way of controlling gas flow.

  • Standing pilot.
  • Intermittent pilot.
  • Hot surface ignition valves, 

It’s common for valves to stick or stop working, leading to breakdowns. Regular maintenance on your gas valve helps prevent issues.

Pro Tip: Always have a professional technician handle any issues with your gas valve. 

Don’t gas out; checking the gas valve is essential for furnace maintenance!

Checking The Gas Valve On the Furnace.

To check the gas valve on your furnace, you need to follow a step-by-step guide to make sure everything is in order with your furnace, especially the gas valve.

 In this section, we will discuss how to check the gas valve on your furnace, outlining the process from start to end. 

We will also explain how to use a multimeter to check a gas valve and show you how to read the voltage on gas valve terminals.

Step-by-Step Guide to check gas valve on the Furnace.

To keep your furnace safe & working well, regularly check the gas valve.

 Here’s a guide:

  1. First, find it near the bottom of the unit.
  2. Then, make sure the furnace is off.
  3. Look for a switch or knob on the gas valve that controls gas flow.
  4. Turn it to the “off” position.
  5. Wait a few minutes for any excess gas to disappear.
  6. Inspect the gas valve for damage or wear. If you spot any cracks or leaks, call a licensed technician.

Remember: This step should only be done by someone experienced in HVAC systems.

Pro Tip: Schedule annual maintenance checks with a licensed technician. This stops any issues from becoming worse.

Pro-tip: If the multimeter reads gas leak, it’s not good!

Using the Multimeter to Check the Gas Valve.

Learning to use a multimeter can help prevent potential hazards from faulty gas valves on your furnace.

 Follow these steps for a safe checking process:

  1. Turn off the power supply to the furnace.
  2. Remove the multimeter leads and connect them tightly to the valve’s terminals.
  3. Set your multimeter to “Ohms” and measure the resistance between the terminal. If it shows infinite resistance or an open circuit, the valve is defective.
  4. Replace your old gas valve with a new one to avoid inaccurate temperature control, wasteful energy bills, or other hazardous risks.

Remember to get a trained technician to replace your gas valves. Regular maintenance schedules can help extend their lifespan. Follow the manufacturer’s manual for advice.

Josef Trumpler invented Gas Valves in 1885, a great invention for industrial automation. It still plays an important role in modern heating systems.

Voltage testing on gas valve terminals is easy. Just be careful!

 Reading the Voltage on Gas Valve Terminals.

When it comes to gas valves on a furnace, checking the voltage on the terminals is key. Here’s how:

  1. Switch off the power at the circuit breaker.
  2. Take off the cover of the gas valve.
  3. Using a multimeter set to AC voltage, touch the probes to the “TH” and “TR” terminals.
  4. Check for 24-28 volts. If you don’t see a reading, there may be a problem with the control board or transformer.

Be aware that some gas valves may only work with certain types of multimeters, so you may need extra equipment. In this case, it’s best to get professional help.

Neglecting your gas valves can be dangerous. Gas leaks or even explosions may happen. So, take care of your heating system with regular checks and professional assistance if needed.

It’s like hide and seek, except you don’t want to be found. And the consequences are serious.

Identifying Issues With Gas Valves On Furnace.

To help you identify issues with the gas valve in your furnace, this section will give you a solution to your problem. 

We will discuss two sub-sections; common problems with gas valves, and troubleshooting techniques.

 By the end of this guide, you will have a better understanding of potential issues with your gas valve, as well as how to troubleshoot and fix them.

Common Problems with Gas Valves.

Gas valves are essential for many appliances that use natural gas or propane. However, like all mechanical parts, they can develop issues with time.

 Here are some common problems with gas valves you should know of:

  1. Stuck valve: Corrosion, dirt or wear can cause a gas valve to become stuck. This can stop the gas flow and make your appliance malfunction. You may hear a humming noise or see a drop in flame size/intensity. Cleaning or lubricating the valve may help, but a replacement is usually required.
  2. Leaking valve: Improper installation, structural damage or aging seals can cause a gas valve to leak. This can lead to hazardous gas buildup and increase the risk of fire, explosion, or carbon monoxide poisoning. You may smell sulfur or rotten eggs near the appliance or see high bills. Shut off the gas supply and call a licensed technician.
  3. Damaged solenoid: A gas valve often has a solenoid that acts as an electric switch. If it’s damaged by voltage spikes, moisture, or debris, it may not work and cause erratic behavior in your appliance. You may hear clicking sounds but no ignition, or vice versa. Testing and replacing the solenoid is necessary.
  4. The wrong type of valve: The gas valve must match the appliance’s specifications. Installing an incompatible valve can result in poor performance or safety hazards. You may experience frequent breakdowns or erratic behavior. Consult a qualified installer before choosing a replacement.

Besides these common problems, there are also several unique details to consider. For instance, you may want to choose a gas valve with a safety shutoff feature. This can prevent gas leaks and fire hazards if the pilot light goes out or if the flame sensor detects abnormal heat. However, such valves may require more maintenance and cost more.

Also, consider the brand and model of your appliance and its warranty coverage. Some manufacturers may require specific types/brands of gas valves

Choosing an incompatible or non-approved valve may void your warranty and expose you to financial risks.

And if your troubleshooting techniques involve hitting the gas valve with a hammer, it’s time to call a professional!

Troubleshooting Techniques For Gas Valve On Furnace. 

Troubleshooting a gas valve is key to keeping appliances in working order. 

  • Before calling a professional, try to see if the pilot light is okay, the valve is open, no leaks, and test the thermocouple. If these steps don’t work, best to get a pro.
  • To stay safe and efficient, check the connection points of the gas lines, and make sure the propane or natural gas supply is connected and sufficient, and there are no blockages in the line.
  • Isolate potential problems by switching off other appliances using the same gas source. This helps see if the problem is specific to one appliance or a bigger issue with the entire gas supply.
  • A faulty valve can be dangerous, so be careful! In 2018, a series of explosions due to pressure valve defects in Lawrence, Massachusetts caused 29 deaths and hundreds of injuries.
  • Be sure to get regular maintenance checks from pros or do routine checks yourself to identify any possible defects with the gas valve before disaster strikes!

 And never forget that not following safety precautions with gas valves can cause explosions that would make Michael Bay jealous!

Safety Precautions And Actions For Gas Valve On Furnace. 

To ensure your safety during furnace repairs, it’s crucial to take necessary precautions and actions.

 In this section, we’ll cover the importance of safety and necessary equipment and tools.

 By understanding these sub-sections, you’ll be better equipped to perform the repair work while minimizing any potential risks.

Importance of Safety.

Safety is super important. We must take steps to reduce the risk of injury or accidents. Everyone should follow safety regulations to keep things running smoothly and protect employees.

  1. Employers must give guidelines and training to identify hazards. 
  2. They should do regular equipment maintenance, inspect work areas, and ensure people use protective gear. 
  3. Employees must stick to procedures and report any unsafe conditions or accidents.
  4. Mental health is also a part of safety. Stress can cause fatigue and physical injuries.
  5.  To be safe, employers should create a positive work environment and eliminate stressors like too much work or substance abuse.

The 1984 Bhopal Gas Tragedy in India was terrible; 15,000 people died due to not following safety standards. We must always prioritize safety and employee welfare. 

Safety regulations must be strictly followed to prevent tragedies like this in the future.

Necessary Equipment and Tools.

To guarantee safety in risky industries, like construction and manufacturing, having the right equipment and tools is key. 

Here are some must-haves:

  1. Hard hats to defend your head from falling debris
  2. Safety goggles to protect your eyes from flying particles
  3. Earplugs or earmuffs to reduce loud noise
  4. Gloves made of strong material, like leather, for defense against sharp or hot surfaces
  5. Certain types of shoes/boots offer solid traction on slippery surfaces and stop falls
  6. A respirator for defense against contaminated air.

Also, you may want to get additional protective gear that’s specific to the industry you are in. For example, firefighting suits and insulated gloves for electricians

Furthermore, inspect your tools and equipment before every project. Make sure they’re in proper functioning condition and fix any defects before starting work. Plus, store them correctly when not in use and keep them in good shape so they’re always ready for use.

 In conclusion, having the correct equipment and tools is fundamental for safety while working. By following these tips, you’ll be better prepared for minimizing risks in hazardous environments.

 Of course, if that professional help comes in the form of mime, it’s probably best to look elsewhere!

Seeking Professional Help For Gas Valve On Furnace. 

To seek professional help with checking your furnace’s gas valve, refer to the following subsections- ‘When to Call an HVAC Technician’ and ‘Things to Keep in Mind when Seeking Professional Assistance.’ 

These subsections will help you understand the signs that indicate calling a professional is the best solution and what you should consider before hiring one. 

Understanding these things will help you get the best out of a professional’s services and ensure the health and safety of your furnace and household.

When to Call an HVAC Technician.

HVAC systems usually go unnoticed until they break down, leaving homeowners feeling uncomfortable. Seeking the help of an HVAC technician is the best way to go. 

  1. Strange noises, bad smells, or airflow issues? Get a professional right away. Delaying repairs can cause bigger problems and even harm your loved ones.
  2. A sign that it’s time to call an HVAC technician is when the system isn’t heating or cooling properly. This could be due to restricted airflow, refrigerant leaks, a malfunctioning thermostat, or a clogged air filter; problems that arise when people don’t do regular maintenance. That means higher utility bills and less comfort.
  3. Heed strange odors coming from your HVAC system. Moldy smells indicate excess moisture while burning smells could mean a gas or electrical malfunctions. Don’t wait for it to become a hazard to your family; call an experienced HVAC technician right away.

Home Advisor recently surveyed and found that the average cost of hiring an HVAC technician ranges from $75-$200 per hour for labor alone

Regular maintenance and timely repairs/replacements are necessary to avoid costly repairs in the future. 

Make sure to get help from a trained professional.

Things to Keep in Mind when Seeking Professional Assistance.

When looking for professional help, consider a few things. 

  1. First, find someone qualified with expertise in the area you need help with. Check their credentials and make sure they have a valid license. Also, understand their fees and payment policies.
  2. Communication is important. Be honest with your concerns and expectations. Ask questions, express your worries, and tell them your goals so they can customize their approach for you.
  3. To get the best out of your sessions, commit to working on yourself and completing any homework or assignments. Know that change takes time, effort, and consistency.
  4. A unique detail: some professionals may offer teletherapy, virtual sessions from the comfort of your own home. Just as effective as face-to-face appointments.

A study by the NIMH shows over 19 million adults received mental health services in 2019. Seeking professional help is an act of courage towards better mental health – not a sign of weakness.

 Don’t be scared; unless you’re a cat. Then it’s okay!

Frequently Asked Questions. 

Q1: Where is the gas valve located on a furnace?

A: The gas valve is typically located near the burner assembly of the furnace. It is usually a metal valve with a knob or lever for controlling the flow of gas.

Q2: What are the initial steps to check the gas valve on a furnace?

A: Start by turning off the power to the furnace and closing the gas supply valve. Then, remove the access panel to gain access to the gas valve.

Q3: How can I visually inspect the gas valve?

A: Look for any signs of corrosion, damage, or loose connections on the gas valve. Ensure that all the pipes connected to the valve are in good condition and properly secured.

Q4: How can I test the functionality of the gas valve?

A: Use a multimeter to check the voltage across the gas valve’s terminals. If there is no voltage reading, it may indicate a faulty valve that needs replacement.

Q5: Are there any safety precautions to take while checking the gas valve?

A: Safety is crucial when working with gas. Ensure that the area is well-ventilated and free from any potential sources of ignition. If you detect a strong smell of gas, evacuate the premises immediately and contact a professional.

Q6: When should I seek professional assistance for checking the gas valve?

A: If you are unsure about your abilities or if you notice any significant issues during the inspection, it is recommended to seek help from a qualified HVAC technician. They have the expertise to handle gas-related components safely.


Having trouble with your furnace gas valve? No need to worry. With the correct tools and info, you can troubleshoot and fix the issue. Listen for clicking sounds or gas leaks. Make sure the pilot light is lit and the flame sensor is clean. If all looks good, it could be a bad gas valve that needs replacing. Use a multimeter to check voltage and continuity at the gas valve terminals. To diagnose the problem, grasp how furnace gas valves work. The gas valve controls gas flow to the burners. It receives signals from the thermostat. It also has safety devices like high-limit switches and pressure switches. Suspect the internal valve isn’t working? Use a manometer to test gas pressure at various points. You may need to check other parts of your HVAC system, such as blower motors or inducer motors. Prioritize safety when working on heating equipment. Unsure how to proceed? Don’t have experience with HVAC equipment? Call a professional technician for help. They have the right tools and knowledge to pinpoint issues quickly and safely. In summary, checking your furnace gas valve requires understanding and tools such as a multimeter or manometer. Prioritize safety. When in doubt, call an experienced technician for repairs or replacements.