While much of our time is spent recommending what you can do to your home to improve its value, and to make it a more enjoyable place to live, we are sometimes remiss in making you aware of certain things that aren't so good.

Well, we found one: Gravity-fed hot water recirculating systems. Although they do conserve water and our hats go off to those who have them for just that reason we strongly recommend against anyone getting one in the future. They are major water heater fuel-wasters. They waste more energy than the pump-driven type. At least the pump-driven type can be controlled (turned on and off) with a timer. These types of pumps are low-energy users. Gravity-fed recirculating systems run nonstop 24 hours a day whether you want them to or not. And this results in a water heater that burns far more often than it should.

Here's how these gravity-fed monsters work:

First, a pipe is run from the top of the water heater into the attic. The pipe runs at a slight uphill slope all the way to the other end of the house where the farthest plumbing fixture exists. At that point the hot water line travels downward to the fixture. The hot water line returns below the floor to the bottom of the water heater. The drain valve at the bottom of the water heater is removed and one side of a tee is connected where the valve existed. The drain is reconnected to one of the two remaining tee ends and the return hot water line is connected to the other. And that completes the circuit.

The system works beautifully (even though it is pressurized), because hot water is less dense than cold water and therefore has the natural tendency to rise. Because the pipe in the attic travels at an ever-increasing slope from the water heater to the other end of the house, the hot water within has a place to rise and therefore constantly seeks a higher level simply and slowly traveling right up the pipe.

This never-ending cycle that operates slowly and steadily, nonstop 24 hours a day is the least cost effective of all of the recirculating systems we know of.

Steve Rivers, a plumbing contractor who had originally installed the gravity system in his own home later added a pump on a timer so he could stop the gravity system from operating. He told us that the gravity system was costing a fortune to operate. Recently, he upgraded that system one more step and added the On Demand type system.