What is a Furnace Gas Valve & How Do They Work? | Spurk HVAC
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What is a Furnace Gas Valve and How Do They Work?

In the world of home heating and comfort, there exists a silent hero that often sits under the radar, but plays a pivotal role in keeping us warm and cozy in those blustery Pennsylvania winter nights. If you’ve ever wondered how your furnace seamlessly starts and stops to maintain your desired room temperature, or if you’re looking to demystify the inner workings of this essential appliance, you’ve come to the right place.

In this article, we’re going to explain what a furnace gas valve is, what it looks like, and how they influence the effectiveness of your home’s heating system.

What is a Furnace Gas Valve?

The furnace gas valve is the heart of your home’s heating system. Its primary function is to regulate the flow of natural gas or propane into your furnace, ignite the flames, and meticulously manage temperature to meet the heating requirements of your home. When a furnace gas valve malfunctions, it not only leads to an inefficient heating process, but also presents serious safety concerns including the potential for a gas leak.

How does a gas valve work and what do they look like?

A furnace gas valve controls the flow of gas into the furnace based on the signals it received from the thermostat. It ensures that the right amount of gas is being delivered for the desired heat. Safety features are integrated to prevent gas leaks and other hazards and in some cases, modern valves can modulate gas flow for more efficient and comfortable heating.

There are primarily two types of gas valves:

  • Single-stage gas valve
    A single-stage gas valve, commonly found within earlier furnace models, operates with just two settings, essentially an “on” and “off” mode, using a solenoid to control the gas flow. When it’s activated, it releases heat at full capacity, which can lead to a host of problems. This includes excessive energy consumption due to the immediate release of maximum heat and a phenomenon known as “short cycling,” where the furnace turns on and off too frequently, disrupting the heating process’s efficiency.
  • Two-stage gas valve (Recommended)
    The more modern and improved two-stage gas valve includes efficient features that can solve many of the problems that come with a single-stage gas valve. It offers an automatic and nuanced approach to heating. It features two settings: “high fire” and “low fire,” effectively preventing the issues encountered with a single-stage valve. The two-stage gas valve can seamlessly switch between these modes in response to thermostat adjustments.

What dangers could a faulty or broken gas valve lead to?

Though a furnace gas valve is an essential component to heating your home, when issues arise they could lead to costly implications for your furnace, and even worse, pose dangers and risks to the health of you and your loved ones.

A faulty or broken gas valve could lead to:

Of course, regular maintenance and inspections are essential, but when issues arise, it’s important to address these dangers immediately by having a qualified HVAC technician inspect and resolve the issue. Safety should always be a top priority when dealing with gas-powered appliances.


Dealing with a component as meticulous as a furnace gas valve requires expertise and experience. At Spurk HVAC, our trained HVAC professionals, with over 20 years of experience, can help you fix any issues that may arise with your furnace. Our complete package of services covers all you need to help maintain your furnace and keep it in pristine working condition.

If you notice that your furnace gas valve is not operating properly, contact Spurk HVAC day (or night) and we’ll arrange for our team to inspect and fix the gas valve and any other issues that may arise. Our 24-hour emergency service allows us to meet your needs when you need us most.

About Spurk HVAC

Spurk HVAC was formed in 2018 and is located in Warrendale, Pennsylvania. We proudly serve Cranberry Twp., Wexford, Gibsonia, Mars, and the surrounding areas. We are an American Standard Customer Care Dealer and a Mitsubishi Diamond Contractor.

We service all makes and models. Please contact us if you are seeking heating repair, heating system replacement, air conditioner repair, air conditioning maintenance, air conditioning replacement, or any other heating & cooling services. Whether you are looking for residential or commercial HVAC services, we look forward to any and all opportunities to become your preferred HVAC contractor.

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Spurk HVAC

Spurk HVAC

Spurk HVAC was formed in 2018 and is located in Warrendale, Pennsylvania. The combined experience of Dale and Jason, along with the desire to build a respectable, family owned business our community can rely on, are the driving factors behind the formation of Spurk HVAC.