We use a humidifier and learned a costly lesson on Saturday. Our furnace was not working so we had someone come out ($175 to show up) and although we put in a new furnace filter in January, the cartridge I put in my humidifier was antimicrobial, not to filter my water since I had quit using distilled water (oops) after a few days. Anyway, we also have a Global Plasma Solutions system installed in our furnace to help purify the air and I leave the fan running 24/7. So, between the two my filter got a film on it, causing the filter to not breathe, therefor shutting off my furnace after a few minutes after I shut down power and rebooted. Moving forward, I will only use distilled water and I will change my filters every month. It was -26 degrees this morning so glad the furnace wasn't the issue - just me having Brain Freeze.