I'm just looking to do a little preventative maintenance. I think my furnace was manufactured in June of 1981 but still seems to work good. I also just discovered that there is a Montgomery Ward whole house humidifier (Signature Series 81-8415) that isn't being used. I would like to get it up and running and order any new parts that I may need. Can anyone point me in the right direction on getting started? Can't find manuals...