A system boiler sits between a regular (hot water only) and combi boiler in terms of function. A system boiler holds its major heating and hot water components within the boiler, then has a separate cylinder to store the hot water.
A system boiler actually works on the same principle as a regular boiler in that it stores its hot water elsewhere, the major difference between the two is the way that the hot water is supplied to the boiler. This means that it can constantly supply hot water to multiple outlets like showers and taps at once go, as opposed to a combi boiler for example, which is designed to only provide hot water to one outlet at a time.
The biggest benefit of a system boiler is that it can provide hot water to multiple taps and showers at once, without losing water pressure to any of them – making it ideal for any home with high hot water usage and multiple bathrooms. Thanks to the hot water tank not only can you have hot water to multiple outlets at once, you can also get hot water to all of them almost instantly.
A system is generally easier to install than a regular boiler since the heating and hot water components are contained within the boiler, and thanks to the condensing technology of modern system boilers the boiler itself is incredibly efficient, with many models achieving 90% efficiency in ideal conditions. This means that for every £1 the boiler takes to run it will use 90p generating heat, with only 10p lost due to wastage, making it an economical choice that could contribute to lowering your bills.
One other benefit of system boilers that is only becoming more relevant as the country moves towards more renewable energy sources is that system boilers have an unvented cylinder which can be altered to heat water using solar power. This means your system boiler will be compatible with solar energy.
The price of a new system boilers will always be in a range, and will depend on a number of factors. System boilers tend to be a little more expensive than a combi boiler, mainly due to the necessity of a hot water cylinder, on top of the boiler itself. Everything from boiler size, to manufacturer, to the types of features you want on your boiler will affect the price you will have to pay.