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Worcester Bosch Greenstar 30i

worcester bosch greenstar 30i
Credit: Worcester Bosch

If you’re looking to replace your boiler, Worcester Bosch will be a name you are familiar with.

They are one of the most popular manufacturers here in the UK with half a century of experience and knowledge. 

They currently design and manufacture a wide range of boilers, air heat pumps, solar heating systems and much more.

They’re also a household name when it comes to high-quality and reliable heating systems.

Worcester Bosch has been operating from the 1960s and has grown substantially over the years into the mammoth boiler production company we know and rely on today. 

We’re going to take a closer look at the Worcester Bosch Greenstar 30i combi boiler to give you a thorough rundown of its specifications and features in order for you to make a sound decision on your next boiler purchase.

In this article on the best-selling Worcester Bosch Greenstar 30i boiler, we examine:

  • Which?’s very high score for the range
  • how and why HomeSage scored them even higher
  • our full review of the Worcester Bosch Greenstar 30i
  • Worcester Bosch Greenstar 30i FAQ
  • getting yourself the best deal on a Worcester Bosch Greenstar 30i

If you’re thinking of replacing your current boiler with a more energy efficient model such as the Worcester Bosch Greenstar 30i, it’s always worthwhile to get a selection of quotes from reputable firms so you can compare your options. 

Here at HomeSage, we want to make this as stress free and quick for you – simply fill in our form with your details.

We will get in touch with 3 or 4 local, trusted and Gas Safe registered boiler installers in your area who will then contact you directly with a competitive quote. 

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The Worcester Bosch Greenstar 30i Combi Boiler achieved an 86% Which? rating

Which? is a consumer advice and information website that is focused on advocating quality products and services for the general public. 

Their mission is to champion the customer and make sure companies are consistently raising their standards of business to deliver the best possible product so that it offers the best value for money.

They grant businesses and products with their ‘Best Buy’ award if they believe that particular product is of exceptional value and calibre.

The ‘Best Buy’ awarded is granted to companies and products across multiple sectors from banking to boilers

Which? also assess boilers through an educated panel who take all elements of the model into consideration and rank the model out of 5. 

The Worcester Bosch Greenstar 30i boiler won the Which? ‘Best Buy’ award in September 2018.

The table below shows the Which? scores for the Worcester Bosch Greenstar 30i boiler:

MeasurementWhich? score
Availability of parts and spares5/5
Brand customer score5/5
Brand reliability5/5
Build quality5/5
Ease of repair2/5
Ease of service3/5
Efficiency rating5/5
Engineer recommendation5/5

Here at HomeSage, we want to help our readers make an informed decision on their new boiler purchase by giving you as much knowledge as possible. 

This is why we have developed our own boiler ranking system.

Our unique system takes into consideration the following factors in order to help you choose a suitable boiler for your needs and budget:

  • the boiler price point,
  • the energy efficiency level of the boiler,
  • the length of warranty provided, and
  • genuine customer reviews and ratings from the Trustpilot website.
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Worcester Bosch Greenstar 30i Combi Boiler (91.16%)

If you’re looking to save money on your heating bill as well as reducing your carbon footprint, installing a modern combi boiler is an excellent choice.

They work by drawing water directly from the mains supply and heating it as it passes through the boiler using a heat exchanger.

This means that you have access to an endless stream of hot water at any time and it never runs out. 

Because combi boilers come in a variety of power output levels and water flow rates, there are a range of options available to you depending on the size and needs of your property.

Unlike traditional or system boilers, combi boilers are fairly small and they can be hung on the wall or hidden out of sight in a cupboard.

Combi boilers also don’t require extra pipework to additional water storage tanks.

The only slight downside of combi boilers is you can lose water pressure if someone else turns the hot tap on at the same time. This doesn’t happen with traditional or system boiler systems. 

Combi boilers are very energy efficient and modern boilers’ general efficiency levels are rated ‘A’ or ‘B’ on the SEDBUK scale.

The more efficient your boiler is, the less you will pay to heat your hot water and home.

So, although it can be a costly installation project, you tend to make the money back in savings over the following few years. 

The Worcester Bosch Greenstar 30i combi boiler has the following specifications:

Make and ModelWorcester Bosch Greenstar 30i Boiler
Efficiency Rating94%
Band RatingA
LPG Compatible?Yes
Parts and Labour Warranty in months60
Heat Exchange Warranty in months60
Output kW30kw
MountingWall Mounted
Flow Rate in litres per second10.8
Price from£1,055
Price to£1,095
ERP WaterA

This boiler is a highly efficient model with a rating of 94% meaning only 6% of the energy is used by the boiler itself to function. 

The total HomeSage score of 91.16% is high which is thanks to the combination of its ‘A’ SEDBUK rating, 10-year warranty option, and competitive price point. 

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Worcester Bosch Greenstar 30i System Boiler (91.07%)

An alternative option to a combi boiler is a system boiler which is a bigger system more suited to larger homes with higher hot water demands.

They store water in an internal storage cylinder after it has been heated. It is a closed system that draws water from the mains supply.

System boilers have a limited storage capacity which can cause inconvenience if you use a lot of hot water in one go. Once the stored water is used, you will need to wait for another load to be heated.

Unlike combi boilers, there are no water pressure issues if more than one member of your home uses the hot water taps at the same time.

They are slightly different from traditional boilers in that they don’t require an additional storage tank in the loft for cold water. 

Make and ModelWorcester Bosch Greenstar 30i Boiler
Efficiency Rating92%
Band RatingA
LPG Compatible?Yes
Parts and Labour Warranty in months60
Heat Exchange Warranty in months60
Output kW30
MountingWall Mounted
Flow Rate in litres per secondN/A
Price from£1,090
Price to£1,135
ERP WaterN/A

As you can see from the results, the system version of this boiler still reaches an impressive 91.07% overall score from us, due to its 92% efficiency rating and 10-year warranty.

The price is slightly higher than the combi boiler model which has marginally affected the overall rating.

Please note that, in this piece, we are primarily discussing the Worcester Bosch Greenstar 30i combi boiler but we have included the system boiler statistics above purely for your information. 

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The Worcester Bosch Greenstar 30i Combi Boiler reviewed

Key features

  • User-friendly controls – even if you’re not technically minded, Worcester Bosch have developed a simple and clear display panel so you can control your heating and hot water with no worries with the one button commissioning mode.
  • Low lift weight – your installer will thank you for choosing this model. Weighing in at 31.7kg, it is considerably less heavy compared to other boilers of similar outputs.
  • Wall mounted jig as standard – as is the rear piping, so installation is easy and straightforward.
  • Accessories available – plug and play accessories available including the option to link to your smartphone to control your heating on the go with the Worcester Bosch app.
  • Clear diagnostics – reduce the amount of engineer callouts with clear self-diagnostics on screen, meaning you can explain to a boiler technician the fault over the phone therefore minimising the possibility of them having to come and check it in person.
  • CondenseSure style syphon inside – means that you greatly reduce the risk of the condensate pipe freezing over, even if you decide to install this boiler in your garage and we have a particularly icy winter and is protected down to -15c.
  • Low energy pump – reduces the amount of electricity the boiler uses to further bring down the cost of running it for maximum financial savings.


This boiler measures in at 710mm x 400mm x 330mm which is fairly standard for a combi boiler but not as compact as other models available.

If you are dead set on installing your boiler within a kitchen cupboard, you may wish to consider the Worcester Bosch Greenstar 25Si Compact.

This has a slightly lower output but is smaller in its dimensions. 


The Worcester Bosch Greenstar 30i comes with a standard 5-year warranty out of the box.

However, you do have the option to extend this to a generous 7-years if you install the boiler through a Worcester Bosch accredited engineer and follow all the rules and regulations.

Most boiler warranties stipulate you register your boiler within 30 days of installation and you service the system annually, and this model is no different. 

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Where is this boiler made?

This boiler is made in the UK Worcester Bosch factory.

This means that you can rest assured knowing you are investing in a quality piece of British engineering and supporting the national economy. 

How much will this boiler cost?

As with all boiler replacements or installations, the cost entirely depends on:

  • your property
  • what system you already have in place and 
  • how much preparation work the installer may need to do to get your home ready for the new boiler. 

You can expect to pay around £1,055 to £1,095 for this boiler.

Remember though that you also need to factor in the cost of installation and other necessary pipe or building work.

There may also be additional chargable extras such as outdoor thermostats or increasing the warranty length. 

Why should I buy this boiler?

Which? didn’t award this boiler its prestigious ‘Best Buy’ award in 2018 for nothing.

This is a superior example of heating technology for smaller or mid-sized homes which have one or two bathrooms (output dependent).

It will provide you excellent energy efficiency so you can enjoy more pounds in your back pocket

The entire Greenstar boiler range from Worcester Bosch has won the Which? award for 7 consecutive years.

This means that you can be sure you are investing in a reliable and high-quality central heating system that will keep your home cosy for years to come. 

According to Trustpilot, Worcester Bosch has a customer service rating of excellent so should anything go wrong, you are in safe hands for a speedy repair

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Get the best deal on a Worcester Bosch Greenstar 30i Combi Boiler

There are thousands of Gas Safe-accredited boiler installers in the UK. By shopping around, you can save up to 54% on the cost of a brand new, fully-installed Worcester Bosch Greenstar 30i for your home.

We’re HomeSage and we work with a nationwide network of checked and vetted boiler installers. By getting multiple quotes from trusted local suppliers, you can save hundreds (occasionally thousands) of pounds.

How? Every fitter is different and the more efficient fitters can make the same amount of profit from an installation charged at a lower price than a less efficient fitter. 

The record gap between the lowest and highest quotes received from installers recommended by HomeSage is 54% – this is a saving which is well worth pursuing.

To get started, fill out the form on this page. We’ll put you in touch with 3-4 local installers – discuss what you need, get their advice, and choose the best deal for you.

Our service is free and you don’t have to accept any of the offers made to you by our partners. 

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Andy is one of the HomeSage founders and an occasional content contributor. His love for boilers is only just outweighed by his love for football.