Combi vs system boiler: which is right for you?

Combi boiler

• Heats water on demand; no tanks or cylinder.
• Frees up space (cupboard and loft).
• Usually cheaper to buy and fit.
• Hot water pressure depends on your mains supply.
• Struggles if two showers run at once.

System boiler

• Stores hot water in a cylinder.
• Handles several taps or showers at once.
• Needs space for the cylinder.
• Pairs well with solar thermal or a future heat pump.

Which should you choose?

For most flats and homes with one bathroom, a combi is the default choice. For larger homes with two or more bathrooms in regular use, get quotes for both.