Last fall I had the smelly Dirty Sock Syndrome on my new Trane dual fuel system. The installer was very helpful and used the treatment prescribed by Trane to spay on the coil to kill the mold. It worked for the year. Then this fall it happened again. He called Trane and they sent him a polymer/acetone mixture to spray on the coil. The desired results would be to seal the coils and copper with the polymer while killing the mold. There is a plastic coating now on the coil. I felt it when it dried. The first night when the machine went into defrost mode, the smoke alarms went off at 3 in the morning. I called the installer back and he found nothing wrong. The mixture must have been sprayed on the heat exchanger during treatment and it burned off. I hope to no adverse effect on our health. I am wondering if the system will work just the same with the coating.
It seems that the aux. heat comes on more now but the temperature plunged as well. I just don't remember the gas part coming on for long periods last year. Maybe because the house was 60 degrees and the thermostat took a couple of days to catch up and get things all warmed up. I use the aspect of the thermostat that reads the indoor temp. to decide if the gas should be used rather than letting the outdoor temp decide. ( can't remember the word for it, sorry.)
I have a long post to ask about the polymer affecting the system in a negative way but I felt the details would help in the advice given. I appreciate any input.