Combination or combi boilers, combine the central heating (CH) with the domestic hot water (DHW) in one box. They are not merely infinitely continuous water heaters having the ability to heat a hydronic heating system in a large house.
Combination boilers consist of a sealed central heating system and a domestic hot water system combined within its casing, View slide
COMBINATION BOILER A gas or oil boiler that heats hot water as it is needed; it therefore needs no separate hot water storage cylinder. A combination (or combi) boiler is like a standard unvented boiler, but with a second heating circuit (the domestic hot water circuit) to provide instant hot water on demand. If the combi is fed directly from the mains water supply to its heat exchanger then, as long as the boiler is firing, there is no limit to the amount of hot water that can be produced. View slide
Combination boilers are especially attractive when space is at a premium, for example in apartments and smaller homes with low/infrequent water consumption, because all water tanks in the loft and even the domestic hot water cylinder is done away with.
How Combi Boilers Work? Combi boilers do not store domestic hot water. They heat water from the cold mains directly even as you use them. With combi boilers, you do not have a hot water cylinder, loft tank, or pipework.
Combis are like standard unvented boilers but they have a second heating circuit, which is what gives you the instant hot water whenever you need it. If fed directly from the main water supply to the heat exchanger, the combi boiler can have an unlimited hot water supply as long as the boiler is firing. Combis manage to extract a larger amount of heat from the flue gases that escape from the flue system, which increases the combi's efficiency.
A combi (or combination) boiler is an ingenious space-saving idea. A combi boiler is both a high-efficiency water heater and a central heating boiler, combined (hence the name) within one compact unit. Therefore, no separate hot water cylinder is required, offering space saving within the property.
Further benefits of a combi boiler are significant savings on hot water costs and the fact that hot water is delivered through your taps or shower at mains pressure. So you can enjoy powerful showering without the need for a pump.
Another combi boiler benefit is that it can generally save you money on installation time and costs, since no tank in the roof space means less pipe work and a shorter installation time.
MAIN COMBI BOILER
Combination boilers are one of the simplest types of boiler, combining two appliances in one; a central heating boiler and water heater. This reduces costs and space replacing a conventional water heater and separate central heating boiler by both powering your central heating system and providing instant hot water, heated straight from the mains.
The Advantages of a Combi Boiler A combi (or combination boiler) is a compact and highly efficient unit giving all the heating and hot water you need, with significant savings on running and installation costs.
Unlike a conventional heating and hot water system, a combi boiler system does not store domestic hot water. It heats water directly from the cold mains – as you use it. There’s no hot water cylinder, no tank in the loft (and so less risk of freezing and flooding), and none of the connecting pipework. So you not only save space, but also reduce hot water costs.
A combi also supplies hot water at mains pressure, giving you exhilarating power showering without the need for a pump. And as, on average, a shower uses considerably less water than a typical bath, the savings on hot water costs and water consumption can be significant.