For those of us who aren't quite as familiar with their tool box, water heaters are just another seemingly self-sustaining part of the home. It is the unsung hero of the hot shower and it isn't until we find ourselves waiting for longer than usual for the bath to warm or abruptly shivering under the shower-head that we really consider it. Those instances can often be far and few between with a good system, so it isn't surprising that they often go without consideration for some time.
However, standing at the ready often makes this single fixture the second largest consumer of energy in the home. At an average 18% of cost, it isn't surprising that some people look to tankless water heaters when considering a way to save over time. Still, like any large purchase, it is important to be familiar with all of your options and understand how they work with your individual situation.
How Water Heaters Work
Both types of water heaters have two use options: gas and electric. The standard electric version runs a current through electrical-resistant heating elements, usually at the middle and bottom of the tank. The standard gas types utilizes a burner situated under the tank and heats the water through the tank itself, which is worth noting that can cause more wear and tear than the electric version. Both heat and store the water for use in their respective tanks.
Most tanks are made of steel and glass-lined on the inside to prevent corrosion, which is the primary reason why tanks fail. A magnesium anode rod also helps this by corroding in it's place, but needs to be checked and, if needed, replaced yearly. The tanks maintain their temperature using insulation and a thermostat that powers each device as needed. When hot water is used, cold water enters through what is called the dip tube to replace it and triggers the thermostat with the change of temperature.
The speed at which the water is heated is called the recovery rate. In general, electric water heaters tend to have a lower recovery rate. However, the capacity and demand of water in the home doesn't always require a rapid recovery rate. So a water heater with a high recovery rate can have a smaller tank and one with a lower recovery rate can make up for it by storing more hot water in a larger tank. A home with a higher demand may require a water heater with both.
Tankless water heaters are, obviously, much smaller fixtures with the removal of the tank. With these, when a hot water tap is turned on, cold water travels into the unit and, as with the standard version, it is heated with either a gas burner or electrical elements. However, the hot water is generally created at a rate of 2 to 5 gallons per minute, which means demand for hot water from several sources can potentially push a tankless water heater to it's limits. More than one unit, either working collectively or separate, can help alleviate the strain.
Pros And Cons
One of the biggest drives for looking into a tankless water heater is that, in only heating water when it's needed, it can reduce energy consumption by up to 34% in homes that use 41 gallons or less a day. This can save families an average of about $100 a year depending on usage. While the initial cost or the system and installation may seem to offset this, their life expectancy is double that of their standard counterparts and requires less maintenance over that time as well.
Size is also often considered. Where the average water heater with tank is 5 feet tall and 24 inches wide, sometimes requiring it's own closet or room, tankless units mounted to the wall measure at 2 feet tall, 1.5 feet wide and 9 inches deep. They also tend to have a cleaner, sleek design that stands out far less than the cylindrical tanks. Still, a variety of sizes from standard tanks can sometimes better meet demands.
As was mentioned before, the lack of a tank means they put out a constant, average flow that can be less capable of keeping up with several uses at the same time. A family with multiple family members utilizing showers, dishwashers and washing machines all at once may require adding more than one tankless water heater to keep up with the demand. However, from a single source, the tankless water heater can maintain a constant temperature regardless of the length of use.
The instant heating also means that, in the event of a power outage, warm water would be completely unavailable until it is corrected. With a tank, you may be able to utilize the water stored for a time.
Find Your Best Fit
If you believe a tankless water heater may be right for you, there are lots of resources to assist you in finding the best fit for you and your individual home or business. Retailers, like the Home Depot, have knowledgeable employees and provide sites with information to help understand the requirements for you and offer selections that meet those needs and your budget. Most local licensed plumbers or plumbing companies are also available to consult or assist with any unique questions regarding water heaters of both varieties, and even provide installation when you decide to make the switch.