My experience in life has taught me that if you are able to break projects up into simple steps, you will become the master of that project. That is the difference between a smart person and a wise person.
Having said that, let us examine how you can install a new or used furnace….. the wise way. I have broken down the process into 13 easy steps. Will you learn everything I know in this article? Of course not. I have installed thousands of furnaces in my lifetime. You will, however, understand the process.
Step 1. Tool list. Nothing is more frustrating than getting started on a furnace job only to find you are missing some of the tools needed to accomplish the job. Most of you already have most of the basic tools you will need. Ex: screwdrivers, drills, hammer, etc. I will help you put your list together so that you will have everything you need before you even begin the job.
Step 2. Assessing your home. You are going to need to understand how your home is made and insulated. Do you have new or old windows and doors? Is there any air infiltrating your home via dryer vents, window fans, etc? Do you have a basement or is your home on a concrete slab? You will need to know this in order to install the correct equipment in your home.
Step 3. Assessing the Heating/Cooling system and duct-work. This is the most important step. Why? The answer might surprise you. It might even surprise some HVAC Contractors. The equipment must be sized right. Hands down. No exceptions. Why? You might be thinking “Doesn’t the rule ‘the bigger the better’ apply here?” No. Let me rephrase that: Heck no!
I will give you a brief example here. If you were to put an over-sized air conditioner in your home, the air conditioner would only run for a few minutes until the thermostat was at the desired temperature. Great! The bigger A/C saved me energy by running a short time, and bringing the temperature down super fast! What’s the problem there? Yes, you did cool your home quickly, but what you did not do was remove humidity (water in the air) from your home. The longer an A/C runs, the more water it removes from the air. That extra water in the air is what makes you uncomfortable in hot weather. The idea is to make you comfortable. Cooling down the house super quick will have the opposite effect. The same principle applies with a furnace. It must be sized properly. There are lots of online heating and cooling calculators out there that are free. Just Google ‘heating and cooling load calculator’. The instructions are usually included. I have included one in a guide that I wrote called “The Ultimate Furnace Installation Guide”. I found that heat/load calculator online for free.
Step 4. Materials list. Ductwork. You will need to keep a running list of materials you will need when you go to the store(for all materials). Perhaps the size of the return needs to be bigger. You no doubt will have to attach the old duct-work to the new furnace. The Installation instructions that come with the furnace will tell you what the sizes will be for a proper installation. All part of Step 3
Step 5. Materials list – Electrical. As you assess your home as part of step 3, you will be able to determine what your new electrical needs will be. Make a detailed list. Keep in mind that all new furnaces need a ground wire. If you do not have a ground wire on your old power supply, you will have to install one.
Step 6. Materials list – Gas line supplies. Also to be determined in step 3. Hopefully by now you see the wisdom of following this process step by step. Making these lists before you start the installation will help you in the long run. With all of the needed materials on hand, as well as a plan of action, you won’t find yourself on the third day of the install, minus 10 degree, and having to run to 15 different stores.
Step 7. Yet another Materials List – Miscellaneous. This will be determined by the type of furnace you have, or will purchase. Ex: an 80% efficient furnace will require different flue pipe materials than a 90% efficient furnace.
Step 8. Finding local suppliers to work with. This might be your biggest hurdle. In the past, you were kinda strapped into your local area suppliers. Nowadays you have the internet. Use it to your advantage. Doing a google search with the words “furnace goodman” will bring up a surprising amount of information. Always make sure to ask about the warranty. Keep in mind here that buying your own furnace saves you thousands of dollars – even if you end up hiring a contractor to install it you for you!
Step 9. Remove power and fuel supply from your existing equipment. Yeah I know, but some folks start ripping things apart and completely forget this step. It’s a reminder.
Step 10. Secure your existing ductwork into place. Why? There is nothing more heartbreaking than starting to remove a furnace, only ot have the existing ductwork fall to the ground at your feet. Not only does this add another day to your job, but also adds new 4 letter words to your vocabulary. Hence, Step 10. Secure the existing ductwork with cleats and screws.
Step 11. Removing the old equipment. Now that you have turned off all power to the furnace, and have secured your ductwork you are ready to start removing the old equipment. Once removed, set it off to the side out of your working space.
Step 12. Putting it all back together. This section is broken up into 6 sub-sections.
Aligning the furnace. If this is done right, you will cut down on the amount of work and ductwork you will have to make
Attaching the Return and Boot to the new furnace
Attaching Old Plenum (ductwork leaving old furnace) to new furnace. This is called the Transition
Reconnecting the gas line, and testing for leaks
Running the flue pipes to remove the spent fuel gases
Reconnection of the thermostat and high-voltage power supply
Step 13. Starting up your equipment. Usually the instructions from the manufacturer will tell you exactly how they would like the new furnace started and tested. Follow their instructions as closely as possible.
There you have it. Twenty years of experience wrapped up in 13 easy steps. If you are thinking of installing your own furnace, I hope this helps you out.
Copyright Gatto Publishing 2008
Although this article is not comprehensive. It should help you decide if you want to tackle a job like this. I believe with minimum handy man skills and my guide, anyone can simply install their own furnace. A complete and comprehensive guide with furnace installation instructions can be found here Furnace Installation. This guide includes all my tips and tricks,(also contractor tricks) and should cut down on install time by a few days.
Also found at The Ultimate Furnace Installation Guide, Free articles on how to solder copper pipe, repair a hydronic hot water system, and many other tools. All that coupled with a forum where you may answer questions, and get replies from experts in the HVAC field – FREE.