Expert Information And Advice On:
DIY Projects, Home Improvement Plumbing, Home Improvement Repair, Home Improvement Remodeling, DIY Repair, Home Improvement Electrical
Project Advice Menu
Home >> Appliance Installation and Repair >>
(This topic is also categorized under Plumbing Projects)
Save with Tankless Water Heaters
What is a Tankless Water Heater?Tankless water heaters, also called Instantaneous or Demand Water Heaters, provide hot water only as it is needed. Traditional storage water heaters produce standby energy losses that cost you money. We do not leave our homes heated while vacationing. We only heat our homes when there is a demand for heat. In the same way, a Tankless Water Heater is used only when there is a demand for hot water.
How do Tankless Water Heaters work?Tankless Water Heaters heat water directly without the use of a storage tank. Therefore, they avoid the standby heat losses associated with storage water heaters. When a hot water tap is turned on, cold water travels through a pipe into the unit. In an electric Tankless Water Heater an electric element heats the water. In a gas-fired Tankless Water Heater a gas burner heats the water. As a result, Tankless Water Heaters deliver a constant supply of hot water. You don't need to wait for a storage tank to fill up with enough hot water.
Typically, Tankless Water Heaters provide hot water at a rate of 2 5 gallons (7.6 15.2 liters) per minute. Ordinarily, gas-fired Tankless Water Heaters will produce higher flow rates than electric Tankless Water Heaters. Some smaller Tankless Water Heaters, however, cannot supply enough hot water for simultaneous, multiple uses in large households. For example, taking a shower and running the dishwasher at the same time can stretch a Tankless Water Heater to its limit. To overcome this problem, you can install a whole house type Tankless Water Heater or install two or more Tankless Water Heaters, connected in parallel for simultaneous demands of hot water. You can also install separate Tankless Water Heaters for appliancessuch as a clothes washer or dishwaterthat use a lot of hot water in your home.
Other applications for Tankless Water Heaters include the following:
Selecting a Tankless Water HeaterBefore buying a Tankless Water Heater, consider the following:
1. Fuel Type
If you plan to purchase an Electric Tankless Water Heater, consider the Electrical Requirements:
If you plan to purchase a Gas-Fired Tankless Water Heater, consider the Gas-Type and Venting Requirements:
You will first need to identify whether your gas type is Natural Gas or Propane. It is imperitive that you examine your current gas line to ensure that it will meet the requirments of your new Gas-Fired Tankless Water Heater. The requirements of the Tankless Water Heater may exceed that of your existing tank-style water heater.
Next, you will need to consider venting requirements for your specific installation scenario. There are a few important things to keep in mind when purchasing the gas venting accessories for your Gas-Fired Tankless Water Heater.
Be sure that you purchase Category III stainless steel (UL1738 certified) venting for your Gas-Fired Tankless Water Heater. "Type B" venting accessories are not acceptable. Also, be sure to check local building code to ensure that your specific needs will be completely met.
Additionally, many Tankless Water Heater manufacturers offer Gas Venting "kits". It is recommended that customers evaluate the needs of their specific installation to ensure that they will be getting all of the necessary gas venting accessories. Depending on where you will be installing the Tankless Water Heater, a pre-made kit will probably not meet your needs. Ensure that you measure out the vent route and consider where the discharge will go through the wall or ceiling, consider the necessary clearances, and consider ample access to air for combustion, then buy the appropriate gas venting pieces. Direct vent gas tankless water heaters bring in fresh air from outside for combustion and vent the flue gas using a blower.
*Note: Gas-Fired Tankless Water Heaters may still require a minimal electrical connection. Be sure to review installation requirements for the units you are considering for purchase.
2. Location, Size, and Demand
The flow rate is especially important, since Tankless Water Heaters will generate a temperature rise based on the flow rate demanded.
For example, a Stiebel Eltron Tempra 12, running on 240 Volt power, will raise the water temperature by 540F at 1.5 gpm, 360F at 2.25 gpm, and 270F at 3.0 gpm, above the ambient incoming water temperature, up to 1250F.
A larger unit, like the Stiebel Eltron Tempra 36, running on 240 Volt power, will raise the water temperature by 920F at 1.5 gpm, 920F at 2.25 gpm, and 820F at 3.0 gpm, above the ambient incoming water temperature, up to 1250F.
This means that if you are using a 1.5 gpm shower and a 1.5 gpm kitchen sink simultaneously, a total demand of 3.0 gpm, the Stiebel Eltron Tempra 12 will raise the temperature 270F, whereas the Stiebel Eltron Tempra 36 will raise the temperature 820F.
Next, you should look at your ambient incoming water temperature. If you live in a cold climate, like New York, your incoming water temperature will likely be much lower than if you live in a warm climate, like Florida. Your best bet is to find out how much temperature rise you will need in order for your hot water to reach the desired heat. If the ambient incoming water temperature for your shower is 650F, you are using a 2.0 gpm shower, and you want to raise that temperature to 1150F, you will want to look for a Tankless Water Heater that will provide at least a 500F temperature rise at 2.0 gpm (1150F - 650F = 500F). However, if you anticipate additional simultaneous demand, such as the hot water from a sink being used while someone is showering, you will need to add the sink's gpm to the shower's gpm in order to determine your overall gpm demand and then find the temperature rise necessary to meet your overall needs.
Single Point Application
Eemax Single Point Electric Tankless Water Heaters
Eemax Flow Controlled
Eemax Flow Controlled Electric Tankless Water Heaters
Eemax Thermostatic Electric Tankless Water Heaters
Eemax Series Two
Eemax Series Two Electric Tankless Water Heaters
Whole House Indoor Use
Eemax EX280T2T Series Three Electric Tankless Water Heater
Whole House Outdoor Use
Rheem Outdoor Gas-Fired Tankless Water Heaters
Tankless Water Heater Installation and MaintenanceProper installation and maintenance of your Tankless Water Heater can optimize its energy efficiency.
Proper installation depends on many factors. These factors include climate and local building code requirements. You should have a qualified, licensed plumbing and heating contractor install your Tankless Water Heater.
Do the following when selecting a contractor:
Be sure you contractor first consults the manufacturer's installation and instruction materials. Manufacturers usually provide the necessary installation and instruction manuals with the product. Your contractor should also contact your municipality for information about obtaining a permit, if necessary, and about local water heater installation codes.
Many Tankless Water Heaters have a life expectancy of more than 20 years. They also have easily replaceable parts that extend their life by many more years. In contrast, storage water heaters last 10 15 years.
You should consult the manufacturer's website or literature, such as the manual, for detailed warranty information.
Periodic water heater maintenance can significantly extend your water heater's life and minimize loss of efficiency. Read your owner's manual for specific maintenance recommendations.
Tankless Water Heater ManufacturersThere are many manufacturers of Tankless Water Heaters, including those below:
The originators of this article and graphical renditions are the professionals at: