On demand hot water systems may have potential as a convenience product if not a water conservation device. Currently they cannot be considered a “must have” product like a clothes washer or dishwasher. Verified water savings will have to improve before utilities spend time and effort promoting these products.
The current stock of on demand hot water heaters could be improved by automating their operation. On many systems the user must activate a pump by pressing a button prior to using hot water. If this activation step could be tied to the faucet mechanism so that turning on the hot water faucet fixture automatically activated the pump, these systems would be much improved.
Point of Use
Point of use hot water heaters may offer an alternative to traditional hot water heating systems for some homeowners. These systems offer some advantages and disadvantage depending upon each individual situation. Point-of-use water heaters are also known as "tankless" heaters because they have no (or only a tiny) storage tank. They are relatively small units that provide hot water on demand. They use gas or electricity for fuel, and can be installed near demand points, such as under kitchen sinks. They are often more expensive than a conventional water heater, but can cost less to operate since they don't maintain a tank full of hot water when not in use. A point of use heater typically provides 1-2 gallons of hot water per minute. Before installing a point of use water heater in your home, make sure its reduced capacity will be adequate for your needs.