How does a System Boiler work?

A System Boiler, or sealed system, is a great option if you have more than one bathroom or your household has a high demand for hot water.


How does a system boiler work?


A system boiler contains all the major components of the heating system, including the pump and expansion vessel, which means installation is quick, neat and efficient. The boiler heats the water in a hot water storage cylinder, which in turn heats the water in the central heating system via a coiled heat exchanger and provides hot water to taps and showers.


Do I need a system or combi boiler?


If you have a high demand for hot water, for example, if you have more than one bathroom or shower room, a system boiler may be the perfect choice for you.


Will I need a separate expansion tank in the loft?


There is no need for a feed and expansion cistern in the loft if you have a pressurised unvented hot water storage cylinder. If you have an open vented hot water cylinder, you will need a cold water storage cistern in the loft.


Can system boilers supply several taps at once?


A system boiler is perfect for homes with multiple bathrooms; hot water is provided by a storage cylinder, so no matter how many taps you turn on, water will not run cold elsewhere in the house.

Our System Boilers

Our System Boiler heats up water in a sealed hot water cylinder, usually found in the airing cupboard, for hot water taps around the home.

Related FAQs

What do Baxi error codes E23, E53, E133, E119 and E128 mean?

Is your boiler shut down and is showing error code E28, E53, E113, E119 or E128? Find out how to fix this...

How long does a Boiler last?

Find answers to how long does a boiler last, when does a boiler need replacing, and how you can make my boiler last longer here...

What is the Boiler Upgrade Scheme?

Find out everything you need to know about Boiler Upgrade Scheme and if you eligible for the Boiler Upgrade Scheme.

Should I turn off my Boiler in the summer?

Is it ok to turn off your boiler in summer? The short answer is: it depends on your home and your circumstances. Find out more...

Why should I have a filter fitted?

Many boiler breakdowns occur are due to sludge in the heating system. Find out the many benefits of fitting a magnetic filter & how it can save you money.

Show more