My brand new, recently installed gas furnace is smoking a little out of the supply lines on the first trial run. Now I applied flex duct tape to all the openings to seal up the duct work for leaks, but I also applied some to the inside of the first starter duct work coming off the top of the furnace by the heat exchangers. Could the tape be melting and burning or do the heat exchangers have to run a while and burn off anything from the factory? This is a gas furnace in a horizontal installation. Please help

<span style="font-weight: bold;">Installing a new furnace</span> 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<span style="font-weight: bold;"> handy person</span> to be able to overcome some of the major hurdles that may be encountered when <span style="font-weight: bold;">changing a furnace.</span><br /><br />The first thing you want to do when <span style="font-weight: bold;">changing out your furnace</span> 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 <span style="font-weight: bold;">smaller furnace</span>, especially if you are changing out an older <span style="font-weight: bold;">inefficient furnace</span> with a <span style="font-weight: bold;">higher efficiency</span> model. Also check that the dimensions of the new furnace will allow it to fit into the same space, and adapt to the existing <span style="font-weight: bold;">supply and return duct work.</span><br /><br />Next you will have to remove the <span style="font-weight: bold;">old furnace</span>. When you do this make sure to carefully plan for the installation of the <span style="font-weight: bold;">new furnace</span>. 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.<br /><br />Remove the <span style="font-weight: bold;">electrical supply</span> and the <span style="font-weight: bold;">gas or oil lines.</span> 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 <span style="font-weight: bold;">air conditioning</span> 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.<br /><br />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 <span style="font-weight: bold;">special license</span> and special equipment to get the job done.<br /><br />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 <span style="font-weight: bold;">gas line</span> and wiring can be installed to the new furnace. I usually make sure to use an approve <span style="font-weight: bold;">flexible gas line</span> so that the piping part is easier. Often the <span style="font-weight: bold;">electrical lines</span> will fit to the new furnace, however if not then changing the wires is really not that hard.<br /><br />Also <span style="font-weight: bold;">MAKE SURE</span> to keep the manufacturer directions!!! Inside the <span style="font-weight: bold;">installation manual</span> there are very clear<span style="font-weight: bold;"> installation instructions.</span> Make sure to follow all of the directions exactly. There also are instructions for the <span style="font-weight: bold;">start up</span> of the furnace in there, those instructions will help you through the <span style="font-weight: bold;">start up and check procedures</span>. <span>Make sure to keep the installation manual for future reference</span>. There are also<span style="font-weight: bold;"> troubleshooting</span> procedures and <span style="font-weight: bold;">flow charts</span> in there that will make <span style="font-weight: bold;">troubleshooting a problem</span> in the future much easier.<br /><br />After over twenty years of <span style="font-weight: bold;">installing furnaces</span> I still get out the installation manual and read it, as they are always changing things that are needed for <span style="font-weight: bold;">proper operation.</span> 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<span style="font-weight: bold;"> materials and tools</span> 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....