Knowing when to replace your furnace gas valve is a vital part of keeping your home comfortable, protected and cost-effective. The gas valve is an often ignored part of your heating system—but without it, your furnace simply won’t work.

In this blog, Jet Electrical, Air Conditioning, Heating & Plumbing will highlight the key signs of a bad gas valve. Whether you’re troubleshooting a potential problem or planning ahead, this guide for Modesto, California, homeowners will help you know when it’s time for furnace gas valve replacement—and how to reach out to the trusted team at Jet Electrical, Air Conditioning, Heating & Plumbing.

What is a Furnace Gas Valve and How Long Does It Last?

To begin, it's important to understand what a furnace gas valve is and what it controls. The furnace gas valve controls the flow of natural gas or propane into the unit's burner assembly, providing the fuel necessary for the combustion process to occur and produce heat. If gas flow is blocked, a gas-powered furnace can't make any heat.

Also an important safety feature, the furnace gas valve is supposed to shut if a problem is detected—preventing a potentially deadly gas leak. The typical furnace gas valve lifespan is about 10–20 years. Though replacement price can change based on the type of furnace and if any other service is required, replacing a furnace gas valve costs an average of between $300 and $800.

The Furnace Won't Light

One of the clues it could be time to replace your furnace gas valve is if the furnace is not igniting or if the pilot light won't light. Gas provides fuel for the flame. Without adequate gas flow through the system, a furnace can't ignite. Occasionally, homeowners also report that the igniter clicks but there's no flame.

However, a furnace not igniting or a pilot light that won't light or stay lit might also indicate  other mechanical issues, such as a damaged sensor, a malfunction in the thermocouple or insufficient fuel supply. If you are dealing with these issues, it's important to call a certified HVAC technician for an inspection. They'll accurately assess whether the problem a thermocouple vs gas valve issue, or if there's another reason your furnace won't light.

Gas Smell Coming from Furnace

One major sign of a malfunctioning furnace gas valve is a strong odor of gas coming from your furnace. This isn’t just a furnace maintenance problem—it’s an urgent safety risk. A gas leak can create a fire, explosion or even CO poisoning. If you smell gas, evacuate the home immediately, call your gas company or 911, and then phone Jet Electrical, Air Conditioning, Heating & Plumbing for emergency furnace repair.

Furnace is Short Cycling

Faulty gas valve symptoms also include short cycling. Short cycling describes when a furnace turns off and on frequently instead of running a full cycle. This may be because a faulty furnace gas valve can produce inconsistent gas flow. The valve malfunction also could force your furnace to shut down to avoid causing a gas leak.

However, sometimes furnace short cycling is the result of different underlying issues, so it's important to seek out a professional HVAC technician for evaluation and possible furnace repair. 

What to Do If You Think Your Furnace Gas Valve Isn't Working?

If you suspect your furnace gas valve isn’t working properly, it’s crucial that you take action immediately.

First, cut off the gas supply to stop the flow of gas, then cut power to your furnace. Don’t try to fix the valve yourself. DIY gas valve repair can pose a safety risk and also might void your warranty and gas valve coverage. Whether the gas valve is stuck open, closed or isn't working for another reason—gas valve repair isn’t a DIY job. In addition, when it comes to deciding between gas valve repair and gas valve replacement, it's usually recommended to replace a gas valve instead of repairing it. 

Call Jet Electrical, Air Conditioning, Heating & Plumbing to Be Sure Your Furnace is Ready for the Modesto, California, Winter

To replace your furnace gas valve safely, contact the professional Modesto, California, HVAC company—Jet Electrical, Air Conditioning, Heating & Plumbing. Our experienced professionals know just what to do when it comes to gas valve troubleshooting. We'll identify the problem, handle the gas valve replacement safely and make sure your furnace is running at peak performance. To save even more power, we can even connect your system with one of our smart thermostats or connect you with furnace installation service to help you replace your old, unsafe furnace.

Don’t delay critical repairs. Call 209-618-4595 today for gas valve replacement services from Jet Electrical, Air Conditioning, Heating & Plumbing.