Thank you for visiting our tankless water heater buying guide page! This guide is intended to help you understand:
A tankless water heater – also known as an “on-demand”, “instantaneous”, “instant”, or “waterless” water heater – is a more energy efficient alternative to a traditional storage tank water heater. Mounted on the wall in your garage, utility room, or outside your home, a tankless water heater can service the hot water heater needs of your entire home, from faucets and showers, to soaking tubs, dishwashers, laundry and more.
Tankless water heaters provide hot water on-demand, meaning that assuming you install an appropriately-sized unit, you can have hot water when you need it, in as many locations as you need it, for as long as you need it. In fact, these are two of the greatest benefits of tankless water heaters: 1) you don’t have to waste energy continuously keeping a large volume of water hot, and 2) you can generate an unlimited flow of hot water, so you don’t have to worry about not having enough hot water to take a long shower or completely fill a soaking tub.
There are three types of tankless units currently available on the market: non-condensing, condensing, and hybrid condensing. While each one operates in a slightly different way, the basic premise for all three is the same. When a tap is turned on, a gas burner ignites and a heat exchanger coil transfers heat to incoming cold water flowing through the coil, delivering hot water to your faucet. (Electric tankless heaters that use elements instead of a gas burner also exist, but aren’t as effective for whole-home use.)
In order to get the water to a sufficient temperature, the units use a high volume of gas, typically between 150,000 and 200,000 BTUs, which in most homes requires the upsizing of a gas line.
A condensing tankless water heater takes things one step further by introducing a second heat exchanger to take advantage of excess exhaust heat, further heating your water and increasing the efficiency while decreasing the operating cost. A hybrid tankless water heater includes a small reservoir of 2 or more gallons to compensate for “short draws” – hot water needs that don’t use much hot water such as hand washing. Keeping this small reservoir full of hot water prevents the unit from having to fully fire up, which increases its overall efficiency.
Important to note: Tankless units do not provide literally “instant hot water”, as hot water still takes time to flow from the unit to the tap.
A tankless water heater is a great solution for a homeowner who currently has a standard tank water heater and is looking to replace it because their current tank is old, inefficient, and/or leaking. Other folks switch to tankless because they simply want to lower their annual water heating bills, and/or use endless hot water. Though tankless water heaters have been in use in Europe and Asia for over 20 years, they are just starting to gain wider acceptance and use in the United States.
Tankless water heaters are gaining popularity for several reasons: a tankless water heater saves valuable floor space in your garage or utility room, lasts 20-30 years because the unit is less susceptible to rust and leaks, can increase home resale value, and is rated at 40-50% more efficient than today’s standard tanks. While the average home using a standard gas tank water heater spends roughly $250 heating their water each year, a tankless heater can bring costs down $75-$120 annually. Whether you’re concerned about environmental impact or just bringing down the cost of heating your water, a tankless water heater is a winner in both of these categories. Some utility companies even offer rebates for installing a tankless water heater.
Another important factor to consider involves the changing federal regulations affecting water heaters, which go into effect in 2015. If you have a gas water heater that’s larger than 55 gallons, from 2015 on, you will be required to install a water heater with at least an 82% efficiency. This rating will only be found in tankless water heaters and more rare, less well-tested condensing tank water heaters.
0.5 – 1.0 GPM
0.5 – 1.5 GPM
1.5 – 2.0 GPM
1.5 – 2.0 GPM
2.0 – 2.5 GPM
1.5 – 2.5 GPM
2.5 – .0 GPM
4.0 – 5.0 GPM
Consider how many of these needs you may have simultaneously to determine the maximum flow rate you require. For a home with 1 bathroom, we recommend 6-7 GPM; 2 bathrooms, 8 – 9 GPM; and 3+ bathrooms, 9-11 GPM.
In our experience, smaller 4-5 GPM units are suitable for studio apartments and small one bathroom homes or other application specific needs. For very larger homes, there are other options including installing multiple tankless units in series.
To get to an average desired hot water temperature of 105-115˚F, your water heater will have to work harder in a northern climate area, so you may have to choose a larger max. GPM flow rate to get the same amount of hot water. Read the charts provided by the manufacturer of your desired brand or ask your water heater installation specialist to help you understand what you need.
When choosing a tankless water heater, the two most important considerations are:
Fuel type: If you currently have a gas tank water heater (natural gas or propane), you can install a gas tankless water heater. However, you will probably have to upsize the gas line coming from your meter to your heater, as tankless units typically require a dedicated line to service their high demands of up to 200,000 BTU.
If you currently have an electric water heater, you will either have to apply for gas or propane service to your home, or connect an existing gas connection to your water heater setup. Some utility companies offer significant rebates for switching from electric water heating to gas water heating, and switching to gas tankless is a great choice and great opportunity to take advantage of these rebates. We do not recommend electric tankless water heaters for most whole-home water heating needs because of the poor feedback, less-than-desirable temperature and flow capabilities of these units.
Location: Determining the desired location of your tankless water heater is important for achieving space savings and most economical installation costs. Talk with your installer about where might be the best place to locate a tankless water heater in your home. You will also need dedicated power to the unit so consider that. Keep in mind, in the event of a power outage, the unit will not provide hot water. However, installers can install a backup battery system if you want.
When estimating a total cost for the installation of a tankless water heater, your installer should go over the current plumbing codes and permit costs with you before they begin work in your home. Make sure you understand the requirements so your water heater is installed safely.
Also, ask your installer to help you understand the periodic maintenance requirements of a tankless water heater. While maintenance costs are low, some manufacturers do recommend a descaling process, the frequency of which will depend on the quality of the water where you live. This will help extend the lifetime of your tank. Read your owner’s manual for further tips and recommendations.
Some utility companies offer incentives to help bring down the upfront cost of purchasing and installing a tankless water heater. Call your utility company to find out about incentives available in your area, or visit our rebates and incentives page.
Call Fast Water Heater Co. TODAY for more information on tankless hot water heaters.