Gradually over the years a lot of things have changed. For instance, gone are the days when running your faucets wide-open produced flows of 10-gallons per minute. Over time water has become much more valuable, and measures have been put in place to conserve water. These days most faucets fixtures have flow restrictors to reduce water consumption. Showers now provide a maximum output of only about 1.5 gallons per minute and the bathroom sinks only about ¾ gallon per minute.
Years ago it was common in expensive homes to find hot water circulating systems that provided the home owner with instant hot water at any fixture in the house. The plumber would run the hot water piping in a loop from the water heater outlet to a fixture and from that fixture to the next and so on until he reached the last fixture. From the last fixture he would run a pipe back to the inlet of the water heater where a pump and check valve were located.
The pipe from the last fixture back to the water heater is known as a dedicated return line. There would be a pump located either at the water heater outlet or at the return line at the water heater inlet, that would circulate the hot water through the hot piping, keeping hot water in the piping all of the time. That way when ever a hot water tap was turned on there would be instant hot water.
Instant hot water is wonderful, but now days this type of system would be expensive. With the full time circulating system you not only pay for the heat energy being lost from the plumbing, but also you pay for the energy to run the pump all the time.
A nice side benefit of instant hot water is the conservation of water. You don’t run thousands of gallons per year of water down the drain waiting for hot water to arrive at your faucet.
Considering the rising costs of both energy and water these days, new technology has came to the rescue. This innovative and patented technology is known as a “temperature controlled hot water recirculating valve”. It uses your existing water pipes and the thermal convection generated by your water heater to circulate the water back to your water heater for reheating (not requiring a pump or any electricity). These systems have a temperature-controlled valve that allows the consumer to easily adjust the temperature control knob to meet their particular needs. There is no water waste with this type of system, and it also minimizes energy waste since it only re-circulates water when the hot water at your faucet cools below your desired temperature. As an added benefit, it can prevent pipe freezing. Installation is a simple DIY., 15-minute project (not requiring any pipe cutting, soldering or electrical connections).