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 overlooked part of your heating system—however, without it, your furnace can’t function.

In this blog, Herman Allen Plumbing, Heating & Cooling will break down the key signs of a broken gas valve. Whether you’re trying to diagnose a suspected problem or thinking proactively, this guide for Mechanicsville, Virginia, homeowners will help you know when it’s time for furnace gas valve replacement—and when to call the experts at Herman Allen Plumbing, Heating & Cooling.

What is a Furnace Gas Valve and Why is It Important?

To start, it's important to learn what a furnace gas valve is and what it controls. The furnace gas valve regulates the flow of natural gas or propane into the unit's burner assembly, allowing the combustion process to occur and produce heat. If gas isn't flowing, 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 dangerous gas leak. The typical furnace gas valve lifespan is about 10 to 20 years on average. While replacement price can change based on the type of furnace and if any other components need fixing, replacing a furnace gas valve costs an average of roughly $300–800.

Your Furnace Won't Ignite

One of the signs 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 is what fuels the burner. Without proper gas flow through the system, a furnace can't ignite. Occasionally, homeowners also hear 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 bad flame sensor, an issue with the thermocouple or low gas pressure. If you experience these problems, it's important to contact a certified HVAC technician for an inspection. They'll professionally diagnose whether the problem a thermocouple vs gas valve issue, or if there's another reason the furnace won't ignite.

Furnace Smells Like Gas

One major sign of a malfunctioning furnace gas valve is a gas smell in your home. This isn’t just a furnace maintenance concern—it’s an urgent safety risk. A gas leak can lead to fire, explosion or even CO poisoning. If you smell gas, leave the home right away, call your gas company or 911, and then phone Herman Allen Plumbing, Heating & Cooling for emergency furnace repair.

Furnace Keeps Short Cycling

Faulty gas valve symptoms also include short cycling. Short cycling describes when a furnace starts, but then quickly stops rather than turning on and continuing through its cycle as usual. This might be occurring because a faulty furnace gas valve can produce inconsistent gas flow. The valve issue also could cause your furnace to stop to avoid causing a gas leak.

That said, sometimes furnace short cycling has other causes, 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 has malfunctioned, 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 attempt to repair the valve without a professional. DIY gas valve repair can result in dangerous situations if done incorrectly and also may 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 comparing options between gas valve repair and gas valve replacement, it's almost always recommended to replace a gas valve instead of repairing it. 

Call Herman Allen Plumbing, Heating & Cooling to Be Sure Your Furnace is Ready for the Mechanicsville, Virginia, Cold

To replace your furnace gas valve safely, contact the professional Mechanicsville, Virginia, HVAC company—Herman Allen Plumbing, Heating & Cooling. Our HVAC experts 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 heating equipment is running smoothly. 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 compromise your safety or comfort. Call 804-979-2758 today for gas valve replacement services from Herman Allen Plumbing, Heating & Cooling.