Condensing vs System Boilers

Q: What’s the difference between a system boiler and a condensing boiler?


A: A Condensing Boiler combines heating and hot water within a single unit. These types of boilers are often used in a domestic setting such as a house or flat where the demands are relatively modest and space is limited. The disadvantages of a condensing boiler are where there is a high demand for hot water such as domestic dwellings with multiple bathrooms. In cold weather conditions, these can impact the heating as a combi-boiler cannot service heating and hot water simultaneously.


A: An apartment block with multiple flats can either have self-contained heating systems, in which a case a condenser boiler depending on hot water demands can be used, or alternatively the boiler could supply all the heating and hot water for every flat, in which case systems boilers would be required. A systems boiler may have up to two or three indepedent boilers to output the higher wattage output required. These boilers often need a boiler room or plant room. A systems boiler is fed directly from the main water supply, heated via a heat exchanger, and stored in a reservoir or header tank ready for immediate use. This means that there is always ample hot water regardless of the amount of hot water required.

Posted in Heating.