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Worcester Bosch Greenstar 21i System Gas Boiler

From: £2,249.00

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Worcester Bosch


Greenstar 21i System Gas Boiler

Is Condensing


Efficiency Rating


Band Rating

A Rating

LPG Compatible


Standard Warranty

Up to 7 Years

Central Heating Max. Output

21.6 kW


Wall Mounted

Flow Rate


ERP Rating

A Heat

Product Description

Designed and manufactured by Worcester Bosch, the Greenstar 21i is a condensing wall-mounted system boiler.

How efficient is the Greenstar 21i?

This is a highly efficient boiler with an efficiency of 94%, which makes it ErP A-rated. Such high levels of efficiency means that it can help to lower your heating bills and your carbon footprint.

Is the output rating suitable for my home?

The Greenstar 21i has an output rating of 21.6 kW which means that it can meet the heating demands of homes with around 15 radiators.

Are any other options available in the range?

There are no shortage of options in the Greenstar i range of system boilers as there are lower outputs of 9 kW to 18 kW as well as more powerful 24 kW, 27 kW and 30 kW models.

Is a system boiler suitable for my home?

System boilers are the best option for medium to large-sized homes with 2 or more bathrooms. This is because of the cylinder which stores hot water.

How long is the warranty period?

A lengthy warranty period of up to 7 years is available when installed by a Worcester Bosch accredited installer.

What are the key features of the Greenstar 21i?

The Greenstar is easy to use and has simple controls with a clear information display that help to make sure you have greater comfort in your home, as well as being good for economy.

This boiler comes with many ways to add reliability such as the low energy pump which helps to reduce for electrical usage, as well as a large condensesure style siphon which is built into the unit to help reduce the risk of frost.

How big is the Greenstar 21i?

This is a compact wall-mounted boiler with dimensions of 710 x 400 x 330 (HxWxD).