Fire and co2 alarm went off as soon as son walked out the shower. The unit was running on cooling. He pressed the button causing the alarms to do the reset and test causing it to say " fire and carbon monoxide." I explained to them how the units work and that the unit is not producing carbon monoxide on cooling and can only produce it when on heating. I showed them 3 times when they press the button it's going to test and alarm them. I also checked the pvc flue pipe just for good measures because when I first did install the customer complained about head aches and I found out that the flue pipe wasn't even connected to the pipe in the attic and I had to redo it. I re asured him that the pipe was connected and sealed and that the unit is not producing any carbon monoxide in cooling.