Tip & How-To about Heating & Cooling
Installing a new furnace can be done by a good handy type homeowner. There are a few things that you will need to know. I will not be able to convey everything that I know in an article such as this, but I will attempt to give the important things that will help the handy person to be able to overcome some of the major hurdles that may be encountered when changing a furnace.
The first thing you want to do when changing out your furnace is to research different new models. Do not assume that you need to same BTU furnace as you have. You may be much better off with a smaller furnace, especially if you are changing out an older inefficient furnace with a higher efficiency model. Also check that the dimensions of the new furnace will allow it to fit into the same space, and adapt to the existing supply and return duct work.
Next you will have to remove the old furnace. When you do this make sure to carefully plan for the installation of the new furnace. By doing some careful planning you can make the hookup of the new furnace much easier. Do not take apart more then is necessary to remove to old furnace. Then position the new furnace to take advantage of as much of the existing parts from the old furnace as possible.
Remove the electrical supply and the gas or oil lines. Then carefully take apart the supply and return duct work. Many times the return duct work can simply be reattached to the new furnace after cutting the appropriate hole into the side of the furnace. As long as you do not have air conditioning on your furnace you can often just strap up the supply duct-work temporarily to the ceiling and hold it there till you can get the new furnace under it again. Many new furnaces are not as tall as the old ones, so you will either need to block up the furnace and shorten the return duct, or you will have to attach it to the existing duct work and then support the supply duct and build new duct to go up to the old supply. Duct-board material is easy to work with and will work well for doing this.
If you have air conditioning on you system you can often support the indoor coil along with the duct-work and just make the swap underneath it. If you cannot do that then you will need to get a professional to help you so that you can pump down and recharge the system. That process takes a special license and special equipment to get the job done.
Now that you have everything removed from the furnace and marked so you know how it goes back together, you can slide the new furnace in place. I usually start by hooking up the supply duct, then the return duct. Once these two major things are in place then the gas line and wiring can be installed to the new furnace. I usually make sure to use an approve flexible gas line so that the piping part is easier. Often the electrical lines will fit to the new furnace, however if not then changing the wires is really not that hard.
Also MAKE SURE to keep the manufacturer directions!!! Inside the installation manual there are very clear installation instructions. Make sure to follow all of the directions exactly. There also are instructions for the start up of the furnace in there, those instructions will help you through the start up and check procedures. Make sure to keep the installation manual for future reference. There are also troubleshooting procedures and flow charts in there that will make troubleshooting a problem in the future much easier.
After over twenty years of installing furnaces I still get out the installation manual and read it, as they are always changing things that are needed for proper operation. However after these many years I also have been able to trim the time down to less then a day for some installations and usually always less then two days for even a difficult one. Your time will be more then that, but with some planning ahead and creating lists of the materials and tools needed you can still get the job done well and in a respectable amount of time. Or you may choose to have some else do it for you....
Posted by D. Floyd... on
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