In combinational boiler system, combi boiler is the only appliance that provides a continual supply of hot water. Combi boiler has two functions. As high­ efficiency water heater it provides instant and unlimited hot water supply for all taps. As central heating boiler, in separate circulation, it distributes heat to all radiators. This solution eliminates the need for installation of a cold water storage tanks, water heaters and other associated components. Boilers of this type have separate temperature control for central heating and domestic hot water.

Combi boiler is the best choice for small properties because standard combi boilers do not have pump and hot water cylinders. They are mains fed and that is why they can supply only one tap with maximum pressure at a time. If someone turns on another tap the flow rate diminishes or can be interrupted. But if your flat or house has only one bathroom, and you do not have to run two taps at the same time, there are many advantages that you should know off. Perhaps this is the right solution for you.

The main benefits include more space and savings on water costs. You do not need to install all appliances used in conventional system and boiler system like for example cold water storage tanks and hot water cylinders. You even do not need pump because you can enjoy hot water at mains pressure. So you have much more space, save money and enjoy unlimited hot water supply but with only one condition: you cannot run two taps with hot water at the same time.

Advantages:

- system more simple and smaller
- much more space
- system more economical, efficient and cheaper to run
- hot water supply instant and unlimited
- drinkable water at all taps

Disadvantages:

- only one tap with hot water may run at the time
- delay in supply off hat water in to the taps (depending on how close the taps are to the boiler)
- no backup for hot water in case of problems with the boiler or gas supply