Tankless Water Heaters: An Upgrader’s Guide

tankless water heater

Homeowners are starting to learn more and more about tankless water heaters.

They save money.

They deliver hot water immediately to the tap.

They can give me endless showers 24/7.

However, the truth is typically less attractive than the myths would suggest. If you are considering upgrading to a tankless water heater, read about some of the costs and benefits here.


Why Make the Upgrade?

Water heaters break down. Perhaps the heating elements fail, the pilot doesn’t light anymore, or the water just doesn’t stay as hot. Long-time homeowners are familiar, at least in part, with failing water heaters primarily because water heaters are built to last, and unless you have a bad heater, it will be quite a few years before yours finally fails.

Do you have to wait until your heater fails before upgrading? Of course not. Many people struggle with their water heaters for many reasons besides direct failure. The primary reason we’ve seen is that some water heaters just don’t put out enough hot water. Depending on the weather, they may also find that it takes too long for hot water to get to the tap or shower.

Making the upgrade can be an issue of convenience or necessity, but your reasons will probably rest on how a tank water heater works compared to a tankless one.


How Do Water Heaters Work?

The main idea behind a water heater is that it keeps water hot for on-demand use. Water heaters do this through two primary mechanisms:

  1. Gas water heaters use a gas flame to heat a tankful of water continuously.
  2. Electric water heaters use submerged heating elements made of metal to heat a tankful of water continuously.

In both cases, the “tank” of the water heater holds all the hot water available for the house. When a fixture draws hot water, it does so directly from the tank, which compensates with cold water that will eventually heat up again due to the energy of the heating element. Therefore, you start to get cold water from a fixture running hot water—the tank has simply run out of reserve heated water and is feeding cold water into the system.

Tank water heaters usually have a thermostat available (more or less—check with your plumber) that allows you to change the heat of the tank at the source.

Tank water heaters typically run into problems after years of service, many of which can be repaired:

electric tankless water heaters

  1. Heating elements break. Whether it is an electrified rod or a gas light, continuous operation can break down the parts in a heating element, necessitating repair. However, while the element is broken, the hot water in the tank will be of a much lower temperature.
  2. The tank itself can cease to trap heat through insulation, resulting in loss of hot water and overall lower temperatures.
  3. The pressure release diaphragm, which prevents cold water from back-flowing into the tank, can become flooded. Once this happens, you may start to run into problems.

These issues aren’t typically that big of a deal and are solved with repair or replacement. Many homeowners, however, run into issues when they want more hot water than the tank can hold, and when they want instantaneous hot water at the fixture. Tank water heaters don’t typically do this.


How Does a Tankless Water Heater Work?

Tankless water heaters, denoted by their name, don’t rely on a tank reservoir to deliver hot water to the fixture. Instead, these units will use an external heating element applied to a pipe that funnels water through the unit so that the water is heated as it flows in and out of the unit itself. The pipes that carry the water through a tankless heater curve back and forth to increase the time water spends in the unit, and to increase the surface area facing the heating elements for each section of the pipe. So, as water enters, it heats during its movement through the heater and comes out hot.

The heating elements are like a traditional water tank: electrical heating elements or gas flame. Each has a distinct benefit, but currently gas tankless water heaters can produce more hot water on demand than electric tankless water heaters.

Depending on use conditions and the environment, tankless water heaters can provide a series of benefits:

  1. Tankless water heaters are more energy efficient than their tank counterparts. Since they don’t need to continually generate heat to warm a tank of water, they reduce overall energy consumption.
  2. Tankless water heaters provide “on demand” hot water. Since there isn’t a tank to run out, that hot water is available immediately, and for as long as you need it.
  3. Tankless water heaters typically last longer, up to 20 years, and take up much less space.


Are Tankless Water Heaters Worth it?

Tankless water heaters do have their specific shortfalls, however, which may convince you to stay with a traditional tank heater:

  1. Tankless water heaters cost more up front, sometimes to the tune of $1,000 or more. That doesn’t include any special installation that occurs when mounting or piping to the unit.
  2. Tankless water heaters don’t push the same volume of hot water throughout a home. While gas tankless heaters can compete with their tank counterparts, they can only do so for low-volume usage (so no multi-shower evenings, especially if the dishwasher is running).
  3. Because of the narrow pip structure (as opposed to a tank), tankless heaters are more susceptible to hard water mineral buildup.
  4. Tankless heaters provide hot water much slower than tank heaters because they don’t have hot water “ready” in a tank when you turn on a hot water fixture.

So, depending on the kind of water your family uses, the size of your home, and the quality of your water, it may benefit you more to stick with a tank.


The Best Water Heater for Your Money

If you are on the market to upgrade your water heater, and you are considering a tankless model, then consider how much you want to invest. On-demand hot water that doesn’t run out can be appealing, as can lower power bills. But you should ensure that your home and lifestyle can be supported by tankless heaters.

First, determine how much water you use. If you have one or two people showering at different times of the night (and not while, say, you run the dishwasher), then a tankless model can work. Likewise, if you have an extremely large house, then the volume of a single unit might not be enough. In either case, realize that you might need a large, expensive tankless heater—or multiple smaller ones.

Also, don’t assume that you’ll get hot water fast. If you want immediate hot water to the fixture, you’re going to have to invest in a water circulation system.

Second, weigh the costs and benefits. A tank water heater is the standard for homeowners and is usually reasonably priced. If you are more concerned with short-term savings than longer-term utility cost cutting, then a tank heater might be a better bet.

Third, consider if the tankless heater will even work with your local water supply. Contact your local water department and find out the mineral makeup of the water supply in your area. You don’t want to have to buy an additional water softener just to protect your tankless water heater.

In any case, the first thing you should do is consult with your plumber. Since they will probably do the installation and upkeep, they can give you the advice you need on whether a tankless water heater upgrade is what is best for your home and family.