What is a combi central heating system?
A combination or ‘combi’ boiler is both a high efficiency water heater and a central heating boiler in a single compact unit. Combi boilers heat water directly from the mains when you turn on a tap, so you won’t need a hot water storage cylinder or a cold water storage tank in the roof space.
What is the difference between a combi and system boiler?
A Combi boiler provides both heating and hot water instantly. A system boiler is designed to work with a cylinder to provide hot water as it does not have the hot water heat exchanger. It contains an expansion vessel and pump allowing the boiler to be installed in a sealed system.
Can a combi boiler run hot water and heating at the same time?
Combi boilers provide a “combination” of instantaneous hot water and effective central heating. Therefore, the system will either transport hot water to your radiators or to your hot water tap – however, this will not be done at the same time and the hot water circuit usually takes priority.
Can you run 2 showers off a combi boiler?
*However combi boilers do not cope well with 2 showers running at the same time in the same property, due to the use of hot water across both showers. This is because combi boilers heat water directly from the mains when you turn on a tap.
What setting should my combi boiler be on?
Modern boilers will have a digital dial where you can set the output temperature. For combi boilers it is recommended to set the output temperature for the radiators at 75 degrees and the water temperature at 60 degrees.
How does the central heating system in a combi work?
The central heating portion of a combi is on a pressurised closed loop system, heated by the boiler as required. For domestic hot water the mains supply is fed direct to the boiler.
What’s the difference between a combi and system boiler?
A system boiler is very similar to a combi but it requires an additional hot water storage cylinder. The system boiler will initially heat the mains water, whilst the hot water cylinder will store and maintain it – so you’ll always have instant hot water on hand.
What kind of boiler does a central heating system use?
The three main boiler types found in a wet central heating system are Combi Boilers, System Boilers and Regular / Conventional Boilers. Combi Boilers – are modern boilers that are responsible for both the heating and hot water in the home. The boiler for both are contained within one single unit, which makes them great space savers.
How much hot water does a combi boiler need?
To have a reasonable level of hot water flow the boiler output has to be in a range of 25-30kW rather than 15-20kW for a system with a hot water storage tank. If you are thinking of using solar water heating in the future then another downside is that these systems are not suitable for use with a combi boiler as they need a hot water cylinder.