Tankless Water Heaters

heating systems and gas supplies

Tired of always having to wait for a few minutes before the hot water arrives, or of running out of hot water? Consider a tankless hot water heater – hot water at your finger tips the instant you need it. Tankless water heaters, also referred to as instantaneous water heaters, provide an endless supply of hot water without using a storage tank. Powered by gas or electricity, tankless water heaters are easy to install, cost effective, a space saver and are designed to last 20 years or more. They can be used as a supplementary source of hot water located at the point of use or can replace your existing hot water heater. Call us today for more information. Learn more about the Bosch Tankless Water Heaters.
If you go to www.protankless.com, pick the model number that you are looking for and email it to us, we will get you a quote.
How Does a Tankless Water Heater Work?
Whenever you turn on a hot water faucet or have a hot shower, cold water travels through a pipe into the tankless hot water unit, where either a gas burner or an electric element heats the water. The faucet acts as a key for turning on the heating element to heat the hot water you need. The water is heated as it flows through the heating elements or heat exchanger. As the water pressure fluctuates, the heating element are adjusted to maintain a constant temperature and maximum energy efficiency. Once you turn the faucet off, the tankless hot water heating system also turns off.
tankless water heatersAdvantages of a Tankless Water Heater
1. Tankless water heaters are smaller, lighter and easier to install than a conventional water heater
2. Unlike a tank water heater, tankless water heaters never run out of hot water.
3. Traditional water heaters take up a lot of space while tankless water heaters hang on the wall saving you considerable floor space.
4. Tank water heaters store water which is a perfect breeding ground for bacteria. Tankless water heaters do not store hot water eliminating the risk of bacteria growth.
5. Tank water heaters have an average lifetime of only 2-9 years while tankless water heaters are designed to last 20 years or more.
6. Tankless water heaters maintain their efficiency for the life of the unit, while a conventional water heater becomes less efficient due to the annual build up of minerals.
7. Tank water heaters have an electric energy factor of .80 to .90 and a natural gas/liquid propane energy factor of .52 to .62. Tankless water heaters have an electric energy factor of .95 to .99 and a natural gas/liguid propane energy factor of .69 to .85.
tankless water heatersFeatures of Tankless Water Heaters

  • Efficiency – the term energy factor characterizes the efficiency of both tank and tankless water heaters. The energy factor is the portion of the energy going into the water heater that gets turned into usable hot water under average conditions. It takes into account heat loss through the walls of the tank, up the flue, and in combustion. The higher the energy factor, the more efficient the heater. Because tankless water heaters don’t have the losses associated with tanks, their energy factors are normally higher (although well-insulated, ultra-efficient tank heaters also have high energy factors). Energy factors for gas tankless water heaters range from around 0.69 to 0.84, compared with 0.55 for a conventional tank and 0.86 for an ultra-efficient tank heater. Conventional electric tank water heaters have an energy factor of about 0.87 compared with 0.91 for an ultra-efficient tank and 0.98 for electric tankless water heaters.
  • Standing pilot or electronic ignitions. Tankless water heaters with standing pilot lights waste energy, but they can be cost effective in applications where water use is high, i.e., in a beauty salon. An electric ignition is your best bet where water use is lower, i.e., in your own home.
  • Modulating or fixed energy input. Older tankless water heaters have a fixed energy output, so water temperatures vary inversely with flow rate. As the flow rate increases (more taps are turned on), the water becomes cooler. Conversely, as flow rate decreases the water becomes warmer. Newer models come with a modulating control that increases or decreases energy input to maintain the desired temperature in spite of varying flow rates and inlet temperatures. Use units with modulating controls when a steady temperature is required and also to prevent scalding in applications where people or animals may come in contact with the water. A modulating unit is not necessary when temperature fluctuations are acceptable as they are in a commercial laundry.
  • Energy inputs. Electric heating element and gas requirements for tankless water heaters are much larger than for storage water heaters. A typical gas storage water heater has a gas input of 40,000 Btu/h. A gas tankless heater, however, may use up to 170,000 BTU/h and so may require larger gas lines and vents than conventional water heaters. Similarly, although a typical residential electric storage water heater draws at most 7,000 watts, a whole house electric tankless heater can draw as much as 19,200 watts, and may require 8 or 10 AWG copper wiring. Specifications for tankless water heaters also include requirements for minimum flow rates to activate them (usually around 1/2 to 3/4 gpm), as well as minimum and maximum water pressure (usually 15 to 150 psi).

Selecting a Tankless Hot Water Heater
Most of us don’t bother looking for a new water heater until its too late. Even fewer are aware that there other options besides the traditional storage tank water heater. Whether you’re replacing an old hot water heater or installing one in a new house, it’s important to look at some of the advantages of choosing the tankless option:

  • Type – there are two main types of tankless water heaters: electric and gas/propane water heaters. Choosing between them depends on how much you want to spend, whether you have access to gas/propane, how much electricity costs and where you live. Most people choose a gas water heater because the cost of gas is approximately one third that of electricity. Gas tankless systems also have wider applications because they produce hot water at higher flow rates. An electric tankless system is an appropriate choice only when gas is not an option and no space is available for a tank hot water heater. Electric or gas/propane heaters can be whole house or point of use.
  • Size or Capacity – Decide the model depending on what capacity or size you need during peak demand, the incoming water temperature, and the desired outgoing water temperature. Most units advertised as whole house tankless water heaters will provide 2 to 3 gallons per minute (gpm) of hot water at a 70°F temperature rise. Choose the model of water heater closest to your flow rate and temperature rise needs. Choose the capacity during peak demand based on the number of users, the number of showers or bathtubs, whether or not you have a dishwasher, and how many hot water devices you expect to have open at one time. Add up their flow rates and this determines your desired flow rate for the demand of water. For example, assume that you want a tankless water heater to operate a shower and kitchen sink at the same time. Most low flow showerheads require about 2 to 3 gpm, and most kitchen sinks about 1 to 15 gpm of mixed hot and cold water. Because showers and kitchen sinks usually use partly cold water, assume your peak demand is 2 gpm for the shower and 1 gpm for the sink, for a total peak demand of 3gpm.
  • Cost Effectiveness – tankless water heaters are the most cost effective when used in high flow rate applications. Because there are so many variables involved in calculating cost effectiveness, it’s a good idea to do your own analysis. Analysis of a hypothetical situation reveals that payback periods for tankless heaters are significantly longer in lower water use applications (68.8 gallons per day) than in high water use applications (250 gallons per day). In the example, tankless water heaters have paybacks ranging from approximately 5.5 to 11 years in low water-use applications compared to approximately 3 to 7.5 years in high water-use applications. It is interesting to note that the tankless heater with a standing pilot light becomes more cost effective than the electronic control unit with the same flow capacity under high flow conditions. This is because when consumption is high enough, the pilot light does not waste a lot of energy. Because the example here includes many assumptions that may be different than your real life situation, we recommend that you use your own figures to determine cost effectiveness. Tankless heaters may become even more attractive when replacement costs are considered, since tank water heaters must be replaced between 6 to 10 years and the tankless heaters last at least 20 years. Other important costs to consider include upgrading energy supply lines and the possibility of hiring an additional qualified technician with experience installing tankless water heaters.

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Tel: 416.492.6444

heating systems and gas supplies

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