Originally Posted By: James Seidel This post was automatically imported from our archived forum.
On Thursday, Dec. 9th I had a new Amana furnace installed in my home, a two story frame with a full basement. The furnace is in the basement. It is model AMS80903BNA, single stage gas fired. It seems to be working properly but the main fan produces a very loud “hum” or “whine” when it runs. I called the installer back and he slowed the motor down from high speed to the correct medium setting for winter operation. That helped a little bit but it still makes a very loud hum compared to the Carrier furnace previously installed in the home. That was replaced because of cracked heat exchangers and was 17 years old. The installer feels the hum is produced by reverberation from the duct work. I called Amana/Goodman in Texas and they said it could be either restricted ductwork or a faulty fan. The hum is not apparent when the furnace is opened and the fan runs and one stands right in front of it. The installer did that so it seems to be working properly. The ductwork is the same as before, there are 7 returns, 4 upstairs and 3 on the main level and outlets in each room. The hum is most apparent in the house rather than near the furnace so the reverberation in the ductwork sounds logical. Any suggestions about what can be done? Any way to isolate the fan or ductwork from the furnace to prevent the loud noise? The installer seems to feel the sound is normal but we are not sure we want to live with it long term. This was a highly rated furnace that was supposed to be quiet . . .
Originally Posted By: rsummers This post was automatically imported from our archived forum.
James could the factory filter still be installed? Most units come shipped with the fan set to the med-low or low taps did they over size your new unit?
Originally Posted By: James Seidel This post was automatically imported from our archived forum.
Factory filter? Where would I look for that? With this install a hole was cut in the right side of the furnace (as you face it) to match the return duct from the previous furnace. The return comes in from the side. The contractor cut a slot in the existing ductwork to allow the filter to slide in and out to be changed easily. The filter is actually external to the furnace with this arrangement and filters the air as it enters from the side. The filter is 16X25X1, a standard size, and the hole cut in the side of the furnace is only slightly smaller so that the filter edge is supported by the perimeter of the opening. Another contractor that installs Trane equipment was going to do the same type of install with that brand of furnace.
As for the fan, it was set to high initially. When I complained about the noise the contractor returned the next day and cut the speed down to the medium setting. That was somewhat better but not really the answer.
Oversized? I have a 2,300 sq ft two story home and a 90,000 BTU unit was installed. The other estimate I received, for the Trane system, was the same size.
I plan 2 things for now:
Ask my neighbors. There are 300 houses in this subdivision with Carrier furnaces that are aging at the same rate. Others have replaced and I will ask them about their noise level and brand installed.
Have another Amana dealer look at the install. Maybe they will see something that I can not and offer some suggestions to correct the hum.
Originally Posted By: Joel Becker This post was automatically imported from our archived forum.
Hi Jim
Sorry I can't tell you what's causing the hum. Just thought I'd let you know, we just installed a new Trane system that is doing the same thing. It is a high-pitched noise that stops when the front panel is removed... probably the same kind of thing. I also tried slowing the motor down and the noise got a little quieter but didn't go away.