Lay down a towel on the floor and run a hot iron over it. Using steam can improve the effectiveness, but be careful not to damage the wood further with too much steam.
Remove Water Stains on Hardwood Floors
Submitted by Andrea · Via http://homeandgarden.chickettes.com/remove-water-stains-from-wood-with-an-iron-towel/
THIS ACTUALLY WORKS!!!! No lie…we’ve had water stains for years that we have been trying to fix with which even word floor specialists couldn’t help us. We were told to do a full refinishing job on all of our floors to fix it. We have young kids and dogs that are continually making messes so we were going to have to wait years to fix the floors. Now we don’t have to do a thing except treat the spots as they appear from “unreported water spills” using this hack. SO HAPPY!!!! THANK YOU!
Details: What seems to work best is the “polyester” setting, moving slow with the iron on the towel, using only a little steam and wiping the area dry from steam moisture after lifting the iron and towel. Redoes are necessary on more severe water stains.