Regular boilers and system boilers have some similarities, but differ in their components:* **Regular boiler (conventional boiler):** Needs several external components, including a cold water tank (usually located in the loft), a hot water cylinder (often in an airing cupboard), and an expansion tank. It takes up considerable space due to the separate tanks..* **System boiler:** Stores hot water in a cylinder but has some key components built in, like the expansion vessel and pump. . It doesn't require a separate feed and expansion tank, saving some space. If you're unsure which type of boiler is best for you, consult with a Gas Safe registered heating engineer.