How to Vent Oil Furnaces

Posted by: Mas Broto
Last Udated:
How to Vent Oil Furnaces

Venting an oil furnace ensures the safety of your home and family members. The process of venting this appliance is not difficult, but it must be done correctly to be effective.

With a direct venting system, you don’t need a chimney. An induced draft fan creates the airflow needed to get the combustion products out of the room through a side wall. Before combustion can start, this system usually needs an airflow-proving switch to ensure that the required draft is there. Discharge fittings are made to go through walls that can catch fire and reduce the effect of wind on how the combustion products escape. Burner, appliance, vent system, and controls all need to be thought of as a whole system, not as separate parts put together.

Venting an oil furnace allows toxic gases and smoke fumes to exit the house safely to the outside. This prevents health problems from gas and smoke buildup. It also prevents a lingering odor inside your home or a nasty residue on your belongings.

Things You’ll Need

  • Flashlight
  • Screwdriver
  • Measuring tape
  • Galvanized steel elbow pipe
  • Electric screwdriver
  • Screws
  • High-temperature silicone
  • Small hand trowel
  • Galvanized steel ventilation pipe

Step-by-Step Instructions – DIY

  1. Look inside the chimney firebox with a flashlight to locate the flue.
  2. Remove the cover that is on the flue. Generally, it is a metal piece attached to screws. Use a screwdriver to remove it.
  3. Measure the diameter of the flue and the distance from the flue to the oil furnace. Take these measurements with you to obtain galvanized steel vent pipes that are the same diameter as the flue. The amount of piping you need depends on the distance from the furnace. An elbow pipe is also necessary to create an L-shaped connection from the flue to the other pipes.
  4. Attach the elbow pipe to the flue opening using an electric screwdriver to add holes and screws.
  5. Seal the flue and elbow pipe where it meets with high-temperature silicone and a small trowel. Allow the high-temperature silicone to dry according to the package directions — typically 20 to 60 minutes.
  6. Attach the other pipes to form the length necessary to reach the oil furnace. Connect them with screws and high-temperature silicone using the same method as the elbow pipe. Wait for the silicone to cure before adding the pipes.
  7. Connect the remaining pipes with the elbow pipe and attach it to the oil furnace, silicone, and screws. Wait approximately 12 to 24 hours before using the oil furnace to ensure the silicone has cured.

Tips & Warnings

Adding insulation around the ventilation pipes after attaching them is a wise way to obtain the most efficiency from your new oil furnace.

If you do not have an existing fireplace and chimney flue, hire a professional to install a vent through the wall. Professionals can safely install a vent for an oil furnace without damaging wiring or compromising the structure of your home.

Final Words

Older oil furnaces are usually less efficient than newer ones. They let a lot of heat and waste products from the burning process go up the chimney. Modern furnaces use efficient technology to use more of this heat in the home instead of letting it go to waste. That means the smoke is cooler now than it was in the past, so there is a less natural lift to help pull it out of the house. Even though the smoke isn’t very hot, using power vents with an efficient oil furnace is a good way to get it out.

mas broto avatar

Mas Broto

Have been in the heating and air conditioning (HVAC) industry for over 20 years. He is person that will grow and thrive to learn more about the HVAC industry throughout his career. Mas Broto is also a blogger, who's dedicated to bringing you the best knowledge to get ahead in the game of life.

Related Posts