We recently moved into our first home in July of last year. When turning on the heat, the furnace was really loud, and had this rattling sound. We had an HVAC company come by to check out our duct work because there were a lot of holes in the ducting. While checking our system, he said that the furnace was old, and based on the sound it was ready to go out. A handy man friend and myself replaced the ducting ourselves, and everything was fine except for the noise, but I supposed that I have gotten used to it. I just have to turn the tv up when running.

Well sure enough the furnace went out, and my retired electrician and expert DIY'er neighbor diagnosed it needing a new inducer fan motor. I could see that the wheel tried to spin, went turning the heat on, but eventually it would stop. I have a LENNOX G16 CONSERVATOR 3 furnace. We then replaced the inducer motor. The heat came back on fine, but i noticed the pilot flame was not behaving correctly. the flame was going in all directions, and was coming out too far in the direction of my face.

i shut it down, and decided to have another HVAC company come out and take a look. He said that wrong inducer motor was installed. A motor for a CARRIER furnace was installed for a LENNOX, and the wheel was spinning the wrong way. He also said that the furnace pressure switch was wired incorrectly, because that was supposed to shut the machine down when it sensed the reversed flow.

I then called the HVAC shop who sold me the part and assured it was the right part for my furnace. The guy on the phone, said that it is the right part, and he meant to tell me that it is reversible, and I needed to reverse it. Ok, we reversed it, and everything worked fine. The furnace was even a little more quiet.

Well, a few days later. The furnace is gradually getting louder, but with no rattling sound. The pilot and actual heating is fine, but is the increasing loudness telling me that thing is about to go? It is tax season, should I just replace? I'd hate to spend the money to replace, but more importantly I'd hate to spend when I don't have too. I would hate to buy a new furnace, and have it be just as loud. I guess the gradual increase in sound is what has me thinking something is wrong.

What you think?