Can A Homeowner Install Their Own Furnace?

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Can A Homeowner Install Their Own Furnace?

I’m not going to get all preachy and say you are incapable of installing a furnace in your Waterford, MI or Oxford, MI home. I am going to tell you it’s not a good idea for two very important reasons:

  1. The smallest mistake by a homeowner installing a furnace can have deadly consequences.
  2. Depending on regulations where you live, it is likely illegal to install your own furnace leading to all sorts of liability issues in the future.


Just about every city or county is going to have licensing requirements to perform HVAC work. There are many good reasons why they exist, including:

  • Installing a gas furnace is complicated.
  • Proper installation requires training and experience.
  • This includes training as a plumber and electrician.

Working with gas and electricity is much different than changing the oil in your car. 


Let me count the ways a homeowner furnace installation can cost money and put you and your family at risk. Here are some of the most common mistakes made by DIY furnace installers:

  • Combustion problems – It takes training, experience, and specialized testing equipment to ensure proper combustion in a gas furnace. If the fuel (gas or propane) is burned inefficiently, it produces higher levels of carbon monoxide increasing the risk of illness or death. 
  • Improper sizing – I can’t tell you how important this is. Most homeowners simply don’t have the training needed to determine the correct size furnace. It’s much more complicated than just knowing the square footage of the house. A trained HVAC technician uses a formula that includes:
    • Number of rooms
    • Room layout
    • Window sizes
    • Insulation quality
    • Plus, many additional factors
  • Reliability problems – There’s a reason why Kotz Heating, Cooling & Plumbing insists the most important day in the life of any furnace is installation day. Any number of problems like poorly designed ductwork or the already mentioned sizing issues will inevitably cause more frequent breakdowns and a shorter lifespan. A professional furnace replacement is the best way to reduce repair costs, achieve the highest efficiency, and increase longevity.
  • Warranty problems – Most furnace manufacturers expect and often REQUIRE professional installation to validate their warranty. A homeowner installation could mean you are left holding the bag for expensive furnace repairs in the future. Is that risk really worth taking?


I really want to emphasize how much respect Kotz Heating, Cooling & Plumbing has for do-it-yourselfers in Waterford, MI and Oxford, MI. But please direct your energy and skills toward more realistic projects that can benefit your family without putting them in danger. Many of the people who work for Kotz grew up as do-it-yourselfers, but now they have the training and experience to handle your furnace installation. Be sure to like us on Facebook and follow us on Twitter for more great HVAC information like this.