Hello all, This is my first post.
I have been struggling with a new furnace for my second winter now. It is a GoodmanCvC9/MVC95- Two stage. We noticed that this new furnace was making a banging sound every time it would light. Also around the same time we noticed an odour constantly around the furnace. I had called the installer and they told me I just needed to take the plastic plug off the side of the furnace and banging would stop. Fair enough I did this and the banging had stopped, however the odour increased.
I called out our local gas company and they came up with a reading always near the third burner. They tagged the furnace and the installer came out switched out the gas valve. This continued for 8 calls to the gas company and I am on the 4th gas valve. At times after a burn (this is when the smell is typically the strongest) the gas company was get readings of 12,000 ppm from what I recall. (Could of been 1200 if the first number seems ridiculous)
My gas meter was also changed outside to make sure there was no movement in the gas lines.
I am wondering if it is the venting (there is nothing stopping the flow, but why would I get a backdraft) since when the plastic plug is out I feel a draft coming through the hole.. even while it is on and running.
Lastly should I have any smell what so ever from this furnace? I have sniffed around other furnaces and smell nothing.. slowly I am going a little crazy.
Thanks for any and all suggestions/replies.