Leaving the water in the tank...
Another reason to empty the tank after EVERY use... bacteria grows in warm, wet places... very quickly. My mom left water in her Rainbow a couple of times and after a day or two it stunk up the house, and left the Rainbow smelly for during use for a couple of weeks. Also, the Seperator needs to be taken off and scrubbed with the tooth brush thing every time it is used to prevent dirt building up and reducing the air flow. I know that Rainbows are a bit of a pain in the arse, all the prep time and take-down time... but, they are very good vacuums. I have an old D3 that I'd hate to have to give up. It may not be a great deep cleaner, like my Kirby GSix, but I do love to use it every so often.
I suggest that you take your grandmum's Rainbow to a reputable vacuum shop and have it throughly serviced. It will make a world of difference. And you really should empty and clean it after every use, that way it lasts a very long time.
Just my two pence.
Justin
