Watched this show on tv about these hot water instant tanks. Its really complicated after reading the companys info sheet. There are so many variables and possible dangers of carbon monoxide. Has anyone used these and really recommend them? I have a 75 gal gas hot water heater now and its almost 18 years old and to my knowledge in very good condition. The problem is that i have to run the water to get hot to do all chores that need hot water. I'm constantly filling up bottles so as not to waste the cool water till it gets hot and use it on my plants. Is it cost worthy? Also, the differences of these tanks and what I read about hot water pumps that u add to your regular hot water tank. From what i understood, that along with those pumps, one has to add a gizmo to each outflow where u want the hot water ie kitchen sink, dishwasher, shower.Of the 2 which would be safer and cost effective? Thanks for any feedback.