Plumbing industry split over water tanks

Q: Dear Mr. Del Grande: We are installing a new bathroom that will use a separate water heater from the rest of the house. Since we’re starting from scratch we can use any type of water heater and we are stumped with regard to using or not using a tankless model.

We have spoken to plumbers who would not recommend them and said we would not be happy with the water flow output. We have also spoken to neighbors that flip houses and say that tankless water heaters are all they install now since they are “the new thing” that potential home buyers are looking for to save energy. Who’s right and who’s wrong, should we go with a tankless or conventional storage tank water heater?

Thanks for your expert advice on this matter.

Judy — Illinois

A: Judy: You raise a topic that is currently splitting the plumbing industry as to the best method to supply hot water to a home.

First, keep in mind that tankless water heaters have been around since the ‘40s and maybe longer than that. So, contrary to popular belief this is not a “new” idea to heat water that is sweeping the industry by storm, and they have been popular in Europe for decades. However, due to applying new technology to an old idea, and a current push to market them, lately tankless water heaters have been getting a lot of attention.

Basically, a tankless water heater works by rapidly heating the water as it passes through a piping coil. Even though a tankless water heater may use more BTUs (energy) while it’s running than a standard storage tank water heater, the mindset is that when there is no need for hot water, you’re not paying to heat the same water over and over as a storage water heater might if it sits idle all day.

However, the plumbers you spoke to have a point. Since basic tankless water heaters may have to restrict the water flow to heat the water quickly and constantly, usually having two or more fixtures running at the same time could draw more water than the tankless heater can supply and hot water flow to the fixtures may slow down.

To put it simply, the general rule of thumb between tankless and storage water heaters is: A basic tankless water heater should give you an unlimited hot water supply with a limited hot water flow, depending on the number of fixtures being used.

While under the same conditions, a basic 50-gallon storage water heater should give you a full flow to each fixture, depending on your house water pressure, with a limited supply of hot water since once the tank is drained of hot water, it will need time to recover. Also, tankless water heaters are generally more expensive than storage water heaters, but in many cases may save energy and last longer than standard tank heaters.

My advice is to completely research the expected hot water draw of your new bathroom, find the equivalent models of a tankless vs. a storage tank water heater, add up the total costs to see what best fits your budget and most importantly will work best with your family’s lifestyle.

This all gets down to personal choices and you may find that after all your hard work, finding the right water heater could be a tankless job!