Combi boilers are economical to run and are able to produce an endless supply of hot water, although the flow may be limited if other taps are running at the same time. The combi boiler delivers hot water at the same speed as your cold taps.
As the combi boiler heats water instantly, direct from the mains, there is no need to wait for a storage cylinder to heat up, and you won’t run out of hot water. There’s also no need for cold water storage tank so it’s perfect if you are limited on space. A pump will circulate the hot water via the pipes and in turn heat the radiators.
A system boiler, just like a regular (conventional) boiler works on the principle of stored hot water. However, a system boiler differs from a regular boiler in some important respects.
Firstly, many of the major individual components of the heating and hot water system are built into a system boiler, which means that installation is quicker, neater, easier and more efficient.
Secondly, the hot water is pumped from the system boiler through the heating system to the radiators and hot water cylinder, resulting in a fast response and more economical running costs. The system boiler removes the need for a feed and expansion cistern.
Regular boilers heat your central heating system directly and produce hot water for your cylinder.
If you are replacing an older model of boiler, the chances are that you will have a regular (also known as “conventional”) boiler.
A typical regular boiler system incorporates a boiler, extended controls, a hot water cylinder which is often fed by a cold water storage cistern located in the loft and a feed and expansion cistern – also located in the loft.