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What You Need to Know About Gas Furnace Installation

When it comes to your home’s heating, cooling and ventilation system, it pays to be patient and to know what you’re doing. The installation of a new or replacement gas furnace can seem like a daunting task. However, when you understand the basic steps in furnace installation, it is much less complicated than you might imagine. This article will show you how to correctly install a new or replacement gas furnace in any room. A gas furnace installation can be complicated, and for those with winter heating needs, you must hire an HVAC Contractor to install your new furnace. This is the best way to avoid future issues and ensure easy access to service on your new unit. Before installing your new gas furnace, be sure to follow these steps:


Installing your new gas furnace can be hazardous. Make sure you are working safely and properly trained to avoid any issues. Only cut wires or plug pipes after first unplugging the unit from the wall outlet. Also, stay in a well-ventilated area when working on your gas furnace installation. In addition to these safety measures, always check your gas supply line for leaks. You can do this with a soapy-water solution similar to a bubble bath with soap and water. Any bubbles signal an issue in your gas supply line that you should call a professional to fix immediately.


When you install a new gas furnace, you will need to be sure that it has the proper venting, an essential step in installing your unit. Improper venting can be dangerous for your family and lead to a high gas bill, which defeats the purpose of installing a completely new gas furnace. You will want to make sure that you are correctly venting your new gas furnace so that it will work efficiently and effectively. Moreover, you will want to do all the work yourself or have a professional install these vents for you.

Prepare Your Site

Before installing your new gas furnace, you should check with the local fire department about their recommendations for your area. This way, you will avoid situations where you might have issues with the fire department when you cannot use or maintain your fireplace or fireplace insert. When painting the room where your new gas furnace will be installed, you must only paint over vents. You should only paint over these vent holes if a metal plate or other material covers them. You can also put a drop cloth on the floor before the vents, so they are not painted over. When painting your room, you should put plain, solid colors on the walls instead of coordinating with your new gas furnace.

Read the Manufacturer’s Instructions

When installing any unit, read the manufacturer’s instructions before you begin. These special instructions will help you know what parts to use, which tools to bring, and how much time it will take. Generally, a gas furnace installation will take anywhere from one to two hours, depending on the size of your home. When installing your new unit, always ensure that all the vents are open and functioning correctly before installing the units themselves.

Position the furnace Properly

Before installing the unit, you will want to ensure that it is positioned in the right place in your house. It is a good idea to empty the room of any furniture or other items. You will not have to move them after installing your new gas furnace. Experts recommend leaving at least two feet between each wall and the space where your venting system will be placed. Also, ensure that this venting system is at least five feet away from any exterior walls.

Electrical Connection

When installing a new gas furnace, you must ensure the electrical connection is completed correctly. This is so that the furnace can work correctly. When you install your new gas furnace, drill pilot holes into your wall to use for your electrical wiring. This will make it much easier for you and your contractor to finish the job successfully. Follow local construction codes and the manufacturer’s recommendations before making electrical connections. Be sure to turn off the furnace’s power supply before beginning the installation process. Verify that there are no current leaks by using a voltmeter.

Gas Line Installation

A gas line installation is essential in installing a new gas furnace. You will need a nearby natural gas supply for your unit to work correctly. Before beginning the installation process, check with your local city building codes and fire department to determine the correct placement of your gas line. When searching for a gas line, you must understand how much natural gas it will take to run your new furnace properly. You should install a separate line for each appliance and shut off each line separately.

Drain Down the Unit Properly

While you are still working with the electrical connections, you should drain down the unit properly. Before draining the unit, ensure all the connections are secure and all the thermostats are set to “OFF.” You will also want to turn off your furnace’s fans or limit their use. When draining down your unit, you will want to open a window in your home to allow heat and moisture to escape naturally. Close this window when it is not raining or snowing outside for an extended period.

Test Run It

Once you are ready to test run your new gas furnace, you will want to keep the safety precautions in mind. For example, ensure the pilot light is lit, and the electrical supply is off. You should also ensure that your carbon monoxide detector is working correctly before starting your furnace for the first time. After these steps are completed, check and confirm your accurate temperature settings. Also, you will want to test the furnace’s heat output. This can be done by closing the furnace intake damper and turning on all exhaust fans. After your furnace has been running for 15 minutes, you should check to see if your home is at a comfortable temperature. You will want to adjust one of your thermostats if it is not.

Maintenance Tips

Take a few minutes to do some simple maintenance to ensure that your new gas furnace continues to work well. For example, you must clean the filter on your furnace once a month. You will also want to check the unit’s pilot light regularly. Check the intake and exhaust fans regularly because they need to be cleaned or replaced if they are not properly working.

Lennox and Coleman furnaces make a range of gas furnaces specifically designed to meet the needs of every homeowner. These furnaces will help you maintain optimal heat in your home and are incredibly efficient.


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