I have a Bryant 90 plus propane furnace that was installed somewhere around '97 or '98. About 4-1/2 years ago the primary heat exchanger was replaced (lifetime warranty). About a month ago I started to hear a faint noise when the draft inducer fan would come on. It sounded like bearing noise. It is making a droning noise that comes & goes as the motor is running (typical bearing noise). It has gotten louder, so I started checking into it. If I remove the front panel from the furnace, you can't hear the noise standing right in front of the furnace. It seems to be more noticeable when you are upstairs where you can hear it coming through the duct work. I have noticed through the sight glass that after the burners ignite, the flames will pulse very slightly in time with the noise. The flame also shows a very slight bit of yellow coinciding with the coming and going of the noise. When not running, the DI motor turns very freely and continues to turn a long time after shutting down as it slows to a stop. The bearings feel good when turning the shaft by hand, and has non of the normal symptoms of bad bearings. A local HVAC tech. says he suspects a heat exchanger (possibly the secondary heat exchanger) problem again. I'm thinking that the flame pulse & slight change of flame color might be due to a problem with the DI. Having never seen the inside end of the DI, I have no idea if there's anything on the inside end that could be causing this problem. Hate to pay to have another heat exchanger put in only to find out that it is a DI problem. Any thoughts on this issue? THANKS

Hi, we have a Trane XR90 that currently is not blowing heat. the red light indicator is flashing 9 times which means it is the ignitor. So I researched the panel and found the HSI but I havent clearly found it on the furnace. I did open the metal box area and see where the flames from the gas would be, the flame sensor, and then a metal popsicle stick looking part that can be disconnected. Is that the ignitor? Please help single mom of 3 kids no heat and just bought christmas gifts so I have to fix this myself. Thank you. I added a photo, the small circle you see is where the flame sensor is and the other part I was thinking is the ignitor. I can take another photo. I took that metal plate off. I did try removing the double wired part that goes right below that metal area, but when I pulled it out there is like a rubber coating over the inside part and I am unable to get it completely out of the space. thanks for reading and hope you can help.