How to Repair a Furnace Gas Valve

How to troubleshoot a furnace gas valve


The gas valve of the furnace is the fuel unit of the furnace. This valve in the furnace can close and open as well. The design of the furnace valve is rather simple. Although, this valve requires proper care and maintenance as it is a very important part of the furnace.

Working of the valve

You should know that there are only specific types of boilers and furnaces that work with the gas valves.

So when there is a unit that works with a gas valve, you will be able to find two units of valves that together make up the gas valve.

The pilot light uses the primary light for gas supply and the burner trays receive gas from the secondary valve which is also called the main valve.

The thermopile is the power generator that opens the primary valve. It is the section of the valve that is submersed in the flame in the pilot light. The thermopile is supposed to be heated right to let the gas valve to stay open. If the furnace valve closes, the pilot light stops receiving gas. This is also a safety design to avoid an accumulation of gas in homes.

All the valves are very safely placed in the right order. Whenever the unit senses an obstruction in the working of the system of the circuit is automatically interrupted.

The furnace gas valve works according to the thermopile. This is the reason how the temperature remains consistent throughout the room and the home.

Know your gas valve type

The two types of gas valves that you can find in the different units of furnaces are gas chain valves and combination valves.

  1. The gas chain valve consists of the solenoid valve, the manual valve, and pilot safety. This type of valve will let you close and open the gas valve manually.
  2. The combination gas valve though does not require all the different valves in the gas chain valve and can function alone in one unit.

Troubleshooting tips for gas valves

  • The pilot light should always be on. If it is not, you will need to light it up. For this, you can follow the manual that might have been provided to you. Or you can always call us to know more.
  • You will have to wait for a little while for the second valve to open as it needs adequate power from the pilot light.
  • The thermopile should be producing an adequate voltage for the primary valve to stay open. There is a definite need for a replacement if the voltage is not enough.
  • In case you would like to know an estimate of the cost of replacement, let us know. We will be happy to help you.


A house with a furnace is very comfortable in the winter season. But the furnace needs to be taken care of to avoid the immature wearing out of its parts. A typical furnace can be used for up to 20 years. However, after a certain point, some issues cannot be neglected. It not only affects the working of the furnace but also the power consumption at your place.

While the furnace might not be in use in the summer season, but you should maintain it and check the parts every few months. Especially before the winter arrives. In some areas, the lack of heat in houses lead to the potential bursting of the pipes after being frozen.

That being said, anything with heat can be extremely dangerous if not maintained properly. And with furnaces, there is always a risk of leakage and fire.

The gas valve is the fuel unit of the furnace and needs to be checked even more carefully. The furnace needs adequate gas supply to be functioning and that can be achieved only when the gas valve is in a suitable condition.


The necessary types of equipment required

If you need to figure out if the gas valve requires replacement then you can contact us for more information.

If you have figured out that your valve requires replacement then you can proceed further. You can always contact us for any assistance needed anywhere in the process.

Here are the things that you will be needing for the replacement:

  • A basic toolkit
  • The accurate valve that you will be replacing your old valve with
  • Contact number to a professional in case of emergency or any other help.

Steps to get started with the replacement

  • Firstly, you will need to cut off the gas supply. This is the first and very crucial step in the process. Leaving the gas supply will lead to gas leakage.

You should be turning off the gas, go to the mains. Turn off the furnace. Check for leakage.

  • Now once the gas supply is checked, you can take the old valve out. Use your toolkit to loosen the screws. Be gentle as you do not want to be breaking the parts. When you have the valve loose, you can take it out by your hand.
  • Fit the new valve. Use your toolkit to fix everything in place as not doing so will be a hazard to your safety. Be gentle and check that the pipes are not getting affected. Double and triple-check that the valve is firmly attached.
  • Check the new valve by turning the gas back on. The pressure must be adequate. If not, you can rest it to get it to work.
  • Always call a specialist before things start getting out of hand. The last thing that you would want is ending up spending way more than you had planned to because of a fault in the process.

You can always use the internet and the tutorials as a guide while changing the gas valve yourself. If you want to know an estimate of your time and expenditure, feel free to contact us. We pride ourselves as being one of the best furnace repair companies in the local area. Contact us today to learn how we can help!


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