How to choose the right combination Boiler

Every day we get calls from customers asking us to quote on either replacing an existing combination boiler with a new combination boiler or upgrading their existing system which involves removing the gas existing boiler, removing the hot water cylinder and also removing the cold water storage tank (proper name cold water cistern) and feed and expansion tank/cistern which are normally located at the highest point in the property i.e. the loft or roof space and to install a combination boiler.

The most important question concerning the installation of gas combination boiler is which boiler will provide the most hot water?

Ask 5 heating engineers the above question and you will get 4 different answers, the reason for this is down to poor understanding of the relationship between water pressure and water flow volume (aka flow rate)

As a customer you simply want the best boiler installed for best value……and not a physics lesson.

This is how to choose the right combination boiler for your property –

Check your water flow rate, see video below and then match the appropriate boiler to your existing water flow rate……..simples.

Existing Water Flow Rate in Your Property

Up to 10 Litres per minute

10 – 12 Litres per minute

12.3 Litres per minute

12.3 – 14.3 Litres per minute

14.3 – 16.4 Litres per minute

16.4 – 17.2 Litres per minute

20+ Litres per minute

If you have 20 litre per minute or more please call us to discuss as you have the option of installing an unvented hot water cylinder or Worcester Bosch Greenstar 440cdi which is the size of a washing machine.

Warning – when you opt for a larger capacity boiler you increase the risk of having to install a new larger diameter gas pipe from the gas meter to the boiler.