Most homes or residences would normally have a central boiler heating unit, and a separate unit that is used primarily for heating water. A recent innovation known as a Combi boiler now combines both functions in a single unit. The use of these units are increasing in popularity, to the point where recent surveys indicate that a Combi boiler was used in over 80% of all the boilers installed in the United Kingdom during the last 24 months.

There are several reasons that can easily be cited for the popularity. There are some significant costs savings that come from the installation. As both functions of the boiler and a water heater are combined, there is no need for storing and heating water. This eliminates the need for hot water cylinders, resulting in a great deal of space being saved.

Since there is no need for any tank to store water, there is also no need for additional piping, which results in a significant amount of time and costs being saved in the installation. While there is no need to store water, savings in energy costs can also be realized, as there is no need to have water being continuously maintained at elevated temperatures. The process produces significant savings in both energy costs and space.

The directly heated water is transported instantly, when needed to outlets such as the faucets and showers. While the water is heated, the heated air is re-distributed to the air circulation units.

There are several additional benefits that may not be as readily apparent. The water used in the heating process is fed directly from the main supply, so there is no reduction in water pressure, since there is no diversion or additional plumbing is required. This will translate to more consistent and higher water pressures.

The Combi boiler contains two heating circuits, and will heat water on demand. One circuit is used to instantly heat, and provide a limitless supply of hot water, that is fed directly from the principal water supply. As the heat is applied directly, it normally takes about 40 seconds to heat the water as it circulates through the heating unit, and because the water is fed from the main supply, there is no need for additional water pumps, as pressure is maintained.

Because the units are compact, they can be easily installed in smaller areas, such as the wall in a kitchen or they can also be hidden in a closet. Installation is much simpler, and will not disrupt other daily needed activities.

With a Combi boiler unit, as the water is directly heated, and supplied as needed, there will be no sudden fluctuations in temperature of the water. The temperatures can be individually controlled at the outlets, such as at the showers, or blended at the faucets or mixed at the dishwasher.

To be beneficial, an adequate supply of colder water must continually be made available to the unit. The colder water is heated and transferred to heat exchanging unit. These units are ideal for single family dwelling homes, or apartments, or perhaps anywhere access to heated water is needed instantly and space is limited.

A Combi boiler is a cost -efficient alternative to conventional heating systems, as they contain both a water heating and heated air supply in a compact unit. The Combi boiler is also easier to install and saves a considerable amount of space.