There are several “recirculating pumps” on the market that solve the problem. Following is one system that was featured on “This Old House” and was easy to install. The D’MAND System is a small, silent pump that you attach to the hot and cold water lines in the cabinet under the most remote kitchen or bath fixture in the home. When the D’MAND System is activated, the cool water you normally let run down the drain is recirculated back to the water heater through the cold water line. On demand, the pump circulates hot water from the water heater and returns the cooled water back through the cold water line. When the hot water arrives at the faucet, the D’MAND System’s patented heat sensor and control board shut off the pump to prevent pumping excess hot water into the cold water line. The system runs only when activated by the user. It automatically senses when water is hot enough. It saves water, energy and money. It saves construction costs - no new return line needed and no need to drain the system. Finally, it is simple to Install.
There are electrical connections to be made. The basic remote switches and power to the pump may require hiring an electrician also. Check with your plumber. He may have an electrician he works with.
If your concern is small amounts of hot water immediately, there is an instant water heater that installs under the kitchen sink with a valve and fill spout at the sink. Electrical connection is needed for this device also.
You will recover some of the cost every month when you pay your water bill. But more importantly, you will no longer have to wait for hot water in the shower or sink and you will wonder why you didn’t do this years ago!
The Metlund system is a nice solution but it has 2 problems.
First you will need an electrical outlet under the sink and in most municipalities you need a permit for that.
Second is that to activate it you need to push a button which also needs to be wired from below the sink to above the sink or use a remote.
Another solution to look at is the WaterQuick Pro II. It installs at the water heater and is activated by turning on any hot water faucet in your home.
The way it operates is turn on a hot water faucet and then turn it off. Wait about 10 seconds and you will have hot water.
The theory behind the system is the same as the Metlund system. However it is a lot easier to install (about 1 hour) and if you are good with a wrench you can do it yourself. Otherwise any plumber or handyman can do it for you.
Google WaterQuick Pro II to get more information.