Facebook pixel
new boiler

Get a new boiler

Fixed price boilers, next day

See boiler prices
new air conditioning

Air Conditioning

Get a quote
new heat pump

Heat Pumps

Coming soon

new ev charger

EV Chargers

Get a quote
boiler servicing

Boiler Servicing

Get a quote

Last updated: 29th November, 2022


Worcester Bosch Greenstar 4000 System Boiler Review

Worcester Bosch Greenstar 4000 System Boiler Review

Today we will review the Worcester Bosch Greenstar 4000 System Boiler, and whether this system boiler is the right choice to keep you and your home toasty.

Worcester Bosch Boilers

As one of the world's leading names in heating innovation, Worcester Bosch, founded in 1962, is synonymous with customer satisfaction.

Blending high end technology with assured traditional engineering, has made the brand one of Europe's most trusted boiler manufacturers.

Need a new boiler?

Get a quote in 60 seconds, fitted as fast as next day!
0% APR finance available.

Get a quote

Worcester Bosch Greenstar System Boiler Range

The Worcester Bosch Greenstar 4000 has been created to follow the form of the extremely popular original Greenstar branch of the Worcester Bosch range.

Combining the latest in heating design and energy efficient application, the Greenstar hallmark represents a modern icon of the boiler industry.

Worcester Bosch Greenstar 4000 System Technical Specifications


Greenstar 4000

Boiler Type 


Energy Efficiency Rating

‘A’ Rated @ 94%


10 years on parts and labour

kW Output


Dimensions (mm) height x width x depth

724 x 400 x 310



Worcester Bosch Greenstar 4000 Key Components And Features - 

  • Full back lit colour LCD display

  • Wide power range to reduce gas consumption and lower energy bills

  • Compatible with unvented indirect cylinders and twin coil cylinders for solar synchronisation

  • Our quietest system boiler

  • Features wireless connectivity with Bosch EasyControl

  • Can be used with Greenskies solar panels for energy and cost savings

Smart Thermostat

The Greenstar 4000 system is fully compatible with smart thermostats like the Worcester Bosch EasyControl system.

This means thanks to the brainy bunch who manufactured your new boiler, it can be easily controlled at the touch of a button for rapid regulation and optimisation.

Eco Friendly 

Our Greenstar system boilers are compatible with Worcester Greenskies solar panels, a clean alternative energy source that reduces carbon emissions and saves money.

Also due to their energy efficient multiple outlet capabilities at one time, system set ups are considered more eco-friendly.

What Is A System Boiler?

A system boiler links with a hot water storage cylinder to provide a home with central heating and hot water. It does this by taking cold water directly from the mains (instead of a cold water storage tank) and heating it via an internal heat exchanger, this transfers gas energy to water.

The hot water is then moved to the hot water cylinder for storage.

Unlike some regular boilers, such as oil or heat only, that use bulky external components, with a system boiler the majority of components are integrated within the appliance.

The only external part is the aforementioned hot water storage cylinder; This is a much smaller unit than some of the other hot water storage tank systems used by regular boilers, these tend to eat up an excessive amount of loft space.

Benefits Of System Boilers

System boilers can cope with the demand of several outlets i.e multiple taps needing hot water at the same time. This makes a system boiler suitable for servicing properties with more than one bathroom.

System boilers can often be installed by a Gas Safe engineer faster than many other boiler types.

Due to an internal pump, and a banked body of hot water, system boilers can produce a stream of hot water on demand quicker than heat only boilers for example.

However if you think your property is more suited to a combi, check out our handy guide to the best combis of 2022 right here!

How Much Does The Worcester Bosch Greenstar 4000 Cost?

Our prices for the Greenstar 4000 system (installation included) start from

15kW - £2,460 Get a quote

18kW - £2,509 Get a quote

21kW - £2,523 Get a quote

Overall the Greenstar 4000 system boiler continues the long line of Worcester Bosch quality home heating, and would be a great option for small to medium sized properties with a high water demand, especially in its larger kW sizes.

Need A New Boiler?

Here at iHeat, we want our customers to receive only the highest quality heating systems, that's why we stock a wide range of Worcester Bosch Greenstar boilers. Get a free fixed price quote online today or get in touch for any enquiries! 

Need a new boiler?

Get a quote in 60 seconds, fitted as fast as next day!
0% APR finance available.

Get a quote

Stephen Day profile photo
Article by
Stephen Day | Co-founder
Gas Safe registered and FGAS certified engineer with over 20 years experience in the heating and cooling industry.