1. What is a combi boiler?

A combi boiler provides central heating and hot water from a single unit. It heats water on demand and does not use a cylinder or tank.

2. What’s the difference between combi boilers, system boilers and heat only boilers?

Combi boilers heat water instantly from the mains and do not use a cylinder or tank. System boilers store hot water in a cylinder, allowing multiple outlets to run at the same time. Heat only boilers use both a cylinder and a cold water tank, supplying stored hot water for higher demand systems.

3. How is boiler size measured?

Boiler size is measured by its power output, rather than its physical dimensions. This is expressed in kilowatts (kW), which indicates how much heat the boiler can produce for heating and hot water. A higher kW rating means the boiler can deliver more heat and support greater hot water demand, such as for larger properties or multiple bathrooms.

Rather place your order over the phone? Trade customers can call us directly to place new orders on 0208 2641 144. Lines open 8am - 10pm 7 days/week.

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