System Boilers Explained
A system boiler heats your home via central heating radiators and stores hot water in a separate cylinder. Unlike a combi, hot water isn't produced on demand — it's pre-heated and stored in the cylinder.
How a System Boiler Works
The boiler heats water, which is pumped around your radiators for central heating. Hot water for taps and showers is stored in an insulated unvented cylinder, heated by the boiler and ready when needed.
Who Should Get a System Boiler?
- Homes with 3+ bedrooms and 2+ bathrooms
- High hot water demand (large families)
- Properties where solar thermal panels will be added (the cylinder can store solar-heated water)
- Homes where multiple showers run simultaneously
System vs Combi: The Key Difference
System boilers deliver hot water at mains pressure from the cylinder. Combi boilers heat water on demand. Systems handle multiple taps simultaneously better; combis are more compact and cheaper to install.
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