Circulation Pumps

Recirculation System

Circulation pumps, also called “recirc pumps” are devices that are installed in plumbing systems to create the circulation of water throughout the system.  They are most commonly used in hot water systems to speed up the delivery of hot water to the fixtures, so that is what we will focus on in this article.

How Circulation Pumps Work

Typically, the pump is installed at the water heater.  The most common method is to install it at the drain bib, located at the bottom of the heater, or at the cold water inlet, so that it draws water from the hot water line and into the heater.

The best way to describe how it works is to first let you know how the hot water system should be laid out in a recirculation scenario.  The main hot water line begins at the top of your water heater.  From there, it should run as close to each fixture as possible.  Once the furthest fixture is reached, a smaller diameter pipe is used (usually 1/2” in a residential home) to go from the last fixture, directly to the pump.  Picture it as a “loop”.

The pump is usually connected to a timer, so that it only works during the times of day when you might need the hot water to save energy.  It will also have a thermostat that connects to the return pipe, just before the pump.  Once the water in the pipe cools, the thermostat triggers the pump to turn on.  The cool water is pumped into the bottom of the water heater, as hot water is drawn through the lines.

A properly laid out recir system will keep the water in your pipes nice and hot, so that you get hot water within a matter of a couple of seconds to each and every fixture in your home.

Some Things You May Want to Know

So, now that you have an idea how they work, here are some other tidbits you may want to know about hot water recirc systems.

  • While recirc systems save water, they do use more energy.  This is because of the electricity the pump uses, and the fact that the water heater works every time the pipes get cold, not just when you need hot water.
  • To improve efficiency (and comply with plumbing code requirements), all of the hot water lines must be insulated.  This keeps the water in the pipes from cooling as fast, so that the pump does not have to work as often.
  • Recirc systems should not be used with a tankless water heater.  The benefit of tankless water heaters is that they only heat the water when you need it.  Since tankless heaters use a LOT more energy to heat water on demand, using a recirc pump with a tankless water heater not only defeats the purpose, but can actually cost you even more money.
  • Circulation pumps have moving parts, and need maintenance, just like everything else.  If you are no longer getting hot water “on demand” or your pump starts making more noise than usual, you should call a plumber out right away.
  • A recirc system should always have a check valve installed, to prevent cool water from entering the wrong way through the return pipe.

Hopefully this article helped you to understand a bit more about circulation pumps, how they work, and whether or not you can benefit from one.  If you have more questions, or think a hot water recirculation system is for you, call Gogo Rooter Plumbing.  One of our expertly training and experienced plumbers will be happy to check out your system and provide you with all the answers you need.

Call us today!