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This FAQ section provides answers to basic and custom questions about water heater systems.

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Technology has come a long way in recent years, and tankless hot water heaters are just one of the many conveniences available to homeowners and business owners. These hot water heaters do not use a standard tank, heating the water directly instead. When hot water is turned on through a tap, the cold water goes through a pipe into the unit. A gas burner or electric element is responsible for heating up the water.
There are a number of benefits associated with purchasing a tankless water heater, including the fact that you will probably never have to worry about running out of hot water again. Those who have a tank unit can use up the overall capacity of the tank, but this is not an issue with tankless models. There is also the energy and cost saving benefits to consider. Tankless water heaters ensure that hot water never runs out while at the same time also guaranteeing a lower utility bill each month. These units are also low maintenance and can be installed almost anywhere.
This really depends upon the hot water demand. A tankless unit heats the water as there is a demand for hot water. The modulating burner adjusts its intensity to match the demand based on the flow rate. As long as flow rate does not exceed heating capacity, endless hot water will be supplied. However, there are situations where it can not respond as quickly as desired or demand outpaces the unit’s capability, creating a hot water flow rate below the desired level.
When it comes to deciding whether to get a gas or electric tankless hot water heater, there are some things to consider about both options. Electric models are typically used for only one sink or a half bathroom setup. These types of tankless hot water heaters require anywhere from 60-150 amps of 220V electricity with a standalone circuit breaker. The fact is that an electric model that is designed for use in a full house may consume more electricity than what it actually needs. Gas models, on the other hand, are better for homes with multiple bathrooms, as they tend to be significantly cheaper and work just as well as electric ones.
GPM stands for Gallons Per Minute, and it is how tankless water heater manufacturers create various sizes for their heaters. With most of these heaters, there is also fine print about the temperature rise of the unit included. Water heaters that use tanks are sold as the total number of gallons that are in reserve for the unit. A standard tank style water heater holds around 40 gallons of water. If you were to compare a 3.2 GPM tankless water heater to a 40 gallon tank heater, the tank unit would run out of water in a matter of 10 minutes at the at the flow rate of the tankless one.
Usually tankless units offer cleaner water in the long term, as they do not accumulate rust and sediment like take models do. Water heaters that use tanks typically develop problems with different types of contaminants that form at the bottom over time, including rust and sediment, which can have an adverse effect on overall water quality.
Tankless hot water heaters can be an excellent option for those who are remodeling or renovating a bathroom in their home. This type of hot water heater can be installed almost anywhere, including a side wall in the basement or even inside the garage. A little bit of plumbing is all that is required to provide the new bathroom with a steady, never-ending flow of hot water. By choosing to install a tankless hot water heater when remodeling this area of your home, you can potentially avoid having to pay for costly updates to the plumbing or needing to install a larger tank style heater to supplement the water supply.
Small businesses, such as gas stations and convenience stores, will find that tankless water heaters can be especially beneficial. These water heaters can easily supply a small commercial building with an adequate amount of hot water for restrooms, and they can be installed in utility closets, basements, and other areas that are out of the sight of customers. Tankless water heaters also help to save on gas consumption and eliminate the need for an open flame pilot light while saving a significant amount of floor/storage space.
Since water flows through the heat exchanger based on flow demand, the unit does not utilize storage capacity. The absence of the storage tank minimizes the physical space required. A tankless unit is typically 13 inches by 24 inches by 9 inches and hangs on a wall. However, most owner’s manuals for tankless water heaters suggest the installation of a drip pan on the floor beneath the heater, which limits use of this space. Many tankless units can be installed outdoors, which can be a real advantage for space savings but it should be noted that in cooler climates additional energy will be used to prevent the tank from freezing.
Efficiency is the amount of energy output as compared to energy input. For example, an 80% efficiency rating indicates that 80% of the heat goes directly into the water, while 20% escapes.
Yes, but not by much –Tankless water heaters are more efficient and have a higher energy factor (EF) since there is no standby heat loss (the loss of heat when stored hot water is not being used). Tankless units can provide an EF around 0.80. tank type water heaters will vary in EF, but range from approximately 0.50 to as high as 0.81, basically matching tankless.
It is common to assume that the absence of a storage tank reduces the potential to leak, but the tankless unit’s internal water flow tubing can be damaged or deteriorate, causing a water leak and significant water damage. Most tankless unit manufacturers suggest the installation of a drip pan under the unit.
More common to tankless water heaters than tank type, a cold water sandwich results from when several “off” and “on” water operations (such as back-to-back showers or washing dishes) create large slugs of cold water between hot water in the piping of a home. Commonly, the piping behind the walls loses heat slower than piping in a crawl space or basement. If there is hot water drawn and then the flow is stopped for a short period of time, the water in the most exposed piping cools off faster than other areas. If someone opens a fixture at the right time, the first water out of the tap is hot, then goes cooler as the water from the exposed piping gets to the fixture. The water from the fixture will heat back up again when water from the heater finally arrives. This situation creates the cold water sandwich.
Most American homes follow the usage pattern of heavy demand for multiple showers or baths during a 60-90 minute period in the morning, followed by another high demand period in the evening with washing dishes, clothes and nighttime showers.
There are several decision factors regarding what is best for your home. Tankless is a great choice for limited usage situations or in steady stream demand. Consideration for usage patterns, multiple hot water needs, ground water temperature, product price, installation costs and other factors will determine which type of water heater is best for your home.