We have a newer (4 year old) furnace, furnace mounted humidifier, and electronic air filter. Just this heating season we have noticed a "bleachy" smell from the cold air ducts I think. It is stronger in the living room than the other rooms. I've taken the cells out of the electronic air cleaner and ran them through the dishwasher (no soap) like the instruction say. I've done this every year with no issue until this year. I have taken apart the humidifer every season and done a good cleaning with CLR and again only this year is the smell around. Does anyone have any ideas?

Thanks.