Three Things to Consider When Choosing a Tankless Water Heater

Many models of tankless water heater can be mounted on a wall, on the floor or on a shelf. (Stiebel/)

The utility bill savings of a tankless water heater can be significant—up to 50 percent off the cost to run a standard full-tank water heater. That makes them a great choice to consider with both new construction or an upfit of an existing water heater. But tankless water heaters have their own considerations, including flow rates per minute and how far the hot water has to travel from the heater to the spigot or appliance. There’s a tankless water heater for just about every application, but not every tankless water heater works for each situation. When you’re ready to save cash on your next hot shower, there are three things to consider when dialing in on a tankless water heater.

This product allows for digital temperature control in one-degree increments. (EcoSmart/)

Tankless water heaters are not one-size-fits-all. You’ll need to calculate how much water flow is required, and match it to the model and size of the heater. It takes about 2.5 gallons per minute of water flow for a single shower. A standard washing machine requires about 2 gallons per minute, and most kitchen sinks need about a gallon-and-a-half. Add up all the household needs to arrive at a required gallons per minute flow.

This convenient model can supply liquid to two sinks at a time. (Bosch/)

Another factor to consider is how quickly and efficiently the heater warms your water. If you live in a colder climate with long bitter winters, the incoming water flow will likely be much colder than if you live in a warmer region; you’ll need a water heater with a greater temperature rise. Tankless water heaters list the details of temperature rise at various gallons-per-minute flows, so check to make sure you’ll be accessing water hot enough for a rousing shower—or four.

An advanced metering system reduces flow when capacity is reduced, so cold showers are a thing of the past. (Stiebel/)

You don’t have to hook up the entire house to a tankless water heater to harness the technology’s cost savings. Small, powerful, under-the-sink heaters provide plenty of hot water for kitchen sink duties at a fraction of the power costs compared to conventional heaters.