Everything You Need To Know About Tankless Water Heaters

You’re exhausted and are so focused on a hot shower that you consider shedding your clothing at the front door. But modesty constrains you, so you act like a responsible adult, put your clothes away, climb into the shower and…

Well, you know the rest. Showers, dishwashers, clothes washers and tasks demanding hot water have already laid claim to the supply. “That’s it,” you declare. “We’re getting a tankless water heater!” Take a breath before you get out the plastic by learning how these handy fixtures work so you don’t get burned.

Tankless Water Heater

Tankless hot water heater technology has been around a while—long enough to acquire a few pseudonyms. When you shop for a unit, look also for “demand-type” and “instantaneous,” both alternative names for a system that delivers hot water without having to be filtered through a traditional tank that heats and serves.

The process of producing hot water that doesn’t require a constant standby energy resource is compelling—particularly since your existing unit sucks up energy 24/7 as it accommodates a continual supply of cold water fed into the tank.

So how do you get hot water in a heartbeat without the clunky metal cylinder? Easy. Turn on the hot water tap and cold water makes its way through the gas or electric element that responds immediately, literally heating each drop as it passes through the conduit.

Sounds good, right? It can be. But current technology has yet to knock out all of the negatives the tankless hot water heater experience offers: today’s unit can process only so much water, which means if you haven’t picked a system that’s big enough to meet your needs, you could wind up with flow rate dilemmas.

According to the U.S. Department of Energy, tankless hot water heaters churn out from two to five gallons of hot water per minute. This amount isn’t set in stone and as a rule, gas-fired units outperform their electrically-powered cousins.

But let’s say that 10 people live in your home. Back-to-back showering could tax a tankless unit to its limit, defeating the purpose of your investment. This is why some homeowners invest in multiple tankless water heaters to expand capacity.

If you’re considering joining the tankless hot water heater movement, you’ll enjoy a better experience if you ascertain whether a “point of use” or “whole house” waterless tank makes more sense for your lifestyle. The first option literally gives you water heating at every source; the second serves the entire house, from dishwasher to bathroom sink.

For the average size family, a tankless hot water heater can be a blessing. These innovations use between 24- and 34-percent less energy to run, so you could lower your power bills. Conversely, tankless units are expensive but they last longer. Water-heated tanks survive around a decade; tankless units can stick around twice that long. The reason? No water in the tank to corrode the shell.

If you’re making this important buying decision, do yourself a favor and factor in the place you live. Groundwater temperatures can dramatically affect the performance of a tankless hot water heater for obvious reasons. Does this mean that Michiganders should have fewer expectations than folks living in Alabama? Perhaps.

Here’s another point to consider: Not every contractor knows how to install a tankless hot water heater, so you may have to search outside your regular contractor network to hire an expert. Want to do the install yourself? Manufacturers supply manuals and materials. That stated, it’s a good idea to check in with your municipal government to make sure you don’t inadvertently ignore local installation codes.

Consumer Reports and other testing entities are currently on the fence when it comes to recommending tankless water heaters and their research shows it can take up to 22 years to break even on the investment you make in one. Further, CR ran simulations forcing 45,000+ gallons of hard water through popular tankless water heater brands and found that promises of “endless hot water” weren’t always true. The publication describes “cold water sandwiches” in-between blasts of hot water as units attempted to keep up with demand.

So what’s your decision? If price is no object and you’d make big sacrifices to enjoy the pleasures only an immediate supply of hot water can bring, one or more tankless heaters may be in your future. These compact units take up virtually no room so you gain storage space once the old one is gone. As a bonus, you can kiss goodbye every homeowner’s nightmare—awakening a 2 a.m. to find a flood caused by a leaky tank. Now that’s priceless.

Charlie Teschner started MESA Plumbing, Heating, and Cooling in 1982. Charlie has a journeyman and master plumber’s license. He was raised with a strong work ethic and he now applies those values to tasks such as heating repair in Boulder.