Recirculation Tankless Installations
Tankless And Recirculation
Some Larger homes may require a recirculation loop so that hot water gets to the desired applications faster. They are commonly used with conventional tanks but certain tankless brands can also be used to fit the bill.
What is a ReCirculation Loop?
The loop usually runs the length of one side of the house and then back along the other side. It should be well insulated and have a continuous flow so that there is always hot water in the loop. This way when someone needs hot water at a shower on the other side of the house it only takes a few seconds for hot water to reach the user. If there wasn’t this recirculation loop the water would need to flow all the way from the other side of the house, this could take few minutes and waste gallons of water.
See the diagram below for a good example
There is not a lot of tankless water heaters that can suitable provide the demands of a recirculation loop. In fact some companies will cut the tankless warranty in half if it is used in a situation where a recirculation loop exists. There are others that don’t modify the warranty and depending on installation Rinnai is one of the brands that allows for a recirculation system. Make sure to talk to your plumber or contractor before begining as they’re a lot of factors to consider before installation.