My furnace wasn't working very well, so I called Paramount Plumbing, Heating, & Air Conditioning. I found their name on a tag attached to my furnace, so I suppose they installed it years ago, before I lived here anyway. The guy who came out saw that the condensation tank hole was clogged and he cleaned it out. That solved the problem. Thanks to Paramount Plumbing, Heating, & Air Conditioning, my house is warm again!