Tankless Coil and Indirect System

Integrated Water Heating System

Tankless Coil and Indirect System

A boiler is basically a box with full of copper tubing that is responsible for heating water quickly to supply heat in the home through a radiator. However, a boiler is different from a water heater, since the latter is responsible in heating water for domestic use, like water for showers and sink. Your existing boiler in your household can be integrated or combined to be used as water heating system. Integrated or combination heating system can be reliable and excellent source of hot water.


A hot water system heating a house is much more efficient and lower cost. It is very popular in the Northeast because of the cold climate.


These type of water heating system is available in the market in an a combined form, incorporating the boiler or furnace and water heater with controls, or as separate components. Boilers typically last long, are reliable, and highly efficient. If it is combined combined with an Indirect Water Heater, it can be one of the best source of hot water for domestic use. The drawbacks of this system is the cost. Typically, it cost more than a separate water heater and furnace or boiler. However, the installation and maintenance costs can be lesser.


There are two styles of integrated system: The Tankless Coil and Indirect System

  • Tankless Coil-Tankless coil water heater delivers hot water only during the demand. Since it is tankless, no tank is needed for this system. The water is heated through a coil or hot exchanger which is connected and installed in the boiler. So, when you open your faucet, the water will flow and pass through the coil to be heated and go through your sink or shower. This system is not efficient during warmer months because the boiler is not in use to heat the home. So, you will just use your boiler to heat water for domestic use. However, during the cold months, this system can be very efficient because of the regular use of the heating system. A tankless system is typically available in electric or natural gas.


  • Indirect System-Indirect systems also heat water in the boiler, but the difference is-it needs a water tank to store the hot water. This system is said to be the most efficient system available. Though the water storage tank will add to the cost, but the efficiency of the system will pay it off. A high-efficiency boiler and well-insulated tank can make an excellent water heating system in your household. This water heating system can be fired with natural gas, oil, propane, electric, solar energy or combination (of what had mentioned)

When considering an integrated water heating system or also known as combination water and space heating systems, you should look into the following:

  • Combined Appliance Efficiency Rating (CAE Rating) – To have an idea of the efficiency of the system, look at the CAE rating. Typically the CAE rating is from 0.59 to 0.90. The higher the number, the efficient it is. So, if you choose the higher number, like 0.85 or higher, the better.
  • Size – When selecting a system, you need to consider its size. The sizing of a combination system involves some different calculations than those used for sizing a separate water heating or space heating system. It’s best left to a qualified plumbing and heating contractor.


Proper and regular maintenance of water heating system is very important to extend the water heater’s life and minimize loss of efficiency. Every water heating system has its proper maintenance recommendation to be followed. Like flushing the water tank bimonthly and checking the anode rod annually are ways of maintaining water heaters. So, if you want water heater to last longer and improves it efficiency, it is important to follow its maintenance procedure.