Fan on furness doesn't run when the AC is on. If I put the fan setting to run, nothing happenes, If I put it on Auto, when the air comes on it will run but it seems a little slow and will not run for long. I think I smell a little ozone when I went in to change the filter but not sure. Have no idea if it runs OK with the furness itself running. It is 100F so I'm not going to even try turning on the heat, even for a little.