Worcester Bosch Boiler Reviews 2021

Worcester Bosch Boiler Reviews 2021 – Which is Best For You?

Worcester Bosch is the UK’s leading domestic gas and oil boiler manufacturer by market share.

They have been highly recommended by Which? for over ten consecutive years now, as well as being recipients of a Royal Warrant for their supply of boilers to properties on The Royal Estate.

In our review of Worcester Bosch gas combi boilers in 2021, we’ll cover:

• who Worcester Bosch is
• what a combi boiler is
• the key stats you need to know about combi boilers and what they mean
• the top 10 Worcester Bosch boilers according to HomeSage’s exclusive grading guide
• Worcester Bosch vs other manufacturers – what do customers think?
• Worcester Bosch’s top 3 small gas combi boilers up to 27kw
• Worcester Bosch’s top 5 medium gas combi boilers from 28kw to 34kw
• Worcester Bosch’s top 5 large gas combi boilers with 35kw+ output

It can be difficult to decide on which boiler is right for you and your property.

In this article, we’ve scored each of the top ten gas combi-boilers from Worcester Bosch according to our exclusive grading guide. 

We’re HomeSage – we work alongside a network of trusted, established Gas Safe boiler installers up and down the UK.

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Once you have sent us your details, we forward these on to three local boiler installation companies in your area.

These companies are keen to give you the most competitive quote to win your order and some customers have reported a 54% difference between the highest and lowest quotes, so shopping around is always worthwhile!

Who is Worcester Bosch?

Worcester Bosch was established in 1962 in Worcester in what was then a thriving post-war Britain – where innovation and opportunity was abundant.

They initially focused their attention on building the best oil-fired central heating systems before eventually developing their own combi-boiler in 1971.

They now have over 2,000 employees, a network of over 300 service engineers, and they serve tens of thousands of customers throughout the UK.

Today, they have over fifty years of boiler development experience and they are even trusted by Her Majesty The Queen to heat the Sandringham Estate!

They are committed to environmental sustainability and they work to a comprehensive environmental policy.

They’re also the company behind the Robert Bosch Foundation which has spent £757 million on improving social initiatives. 

What is a combi boiler?

A combi-boiler heats water as it passes through the boiler directly from your mains supply.

When you turn on the hot tap, the internal gas burner is ignited and a heat exchanger heats up the water – meaning you get hot water almost instantly. 

It’s the same for your heating – the water is heated up by your combi boiler and then it’s piped through to your radiators as soon as you turn it on.

Combi-boilers are cost-effective and energy-efficient. What’s more, they work particularly well for smaller properties as they take up very little space.

They can be stored within your kitchen cabinet units or in a utility room – and you don’t need a loft for a water storage tank.

They are usually cheaper to install as you don’t need to plumb pipes up to your loft as you would with a regular boiler, and, as there’s no pipework in the loft, you eliminate the worry of them freezing over in cold weather.

Check out our article on the best combi boilers on the market in 2021!

Key combi boiler stats

When you’re deciding on which combi-boiler to go for, you’ll need to consider a few facts when coming to your judgement.

To make sure you are choosing the best boiler for your property size and needs, you should look at the flow rate of the boiler, its output, and its energy efficiency. 

Combi boiler flow rate

A boiler’s flow rate represents how many litres of hot water your boiler can heat and distribute in one minute.

This is determined by the amount of water provided by the mains supply and the capacity of your boiler to heat it.

The more powerful a boiler is, the quicker it will be able to provide you with hot water.

Flow rate is also entirely dependent on the amount of water entering your property from the mains supply as this is the maximum amount you can get.

If your boiler has a flow rate of 14 litres per minute, but the mains only allows you 10 litres, your maximum amount will still be 10 litres.

Combi boiler output

Boiler output refers to how much energy your boiler uses when it’s working, and it’s important to know, as the output rate tells you how much your boiler will cost to run.

To work out how much it will be, you multiply the output by the price of a unit of gas. 

For example, if you have a boiler with an output of up to 27kW and the price of a unit of gas is 4p, each hour the boiler is switched on will cost you 27 x 4p – which equals £1.08. 

You need to choose the right amount of ‘output’ for the size of your home and how much hot water you will need.

The higher the amount required, the higher the output needs to be.

For medium sized homes with 3 or 4 bedrooms and up to 15 radiators, a 28-34kW boiler is usually recommended. 

Combi boiler energy efficiency rating

Boiler efficiency refers to the percentage of energy used by the boiler to do its two jobs correctly – to heat your home and to provide you with hot water.

When a boiler is working, a percentage of energy used goes to heat up the water and a smaller amount of energy is used by the boiler itself for non-productive internal functioning – this percentage is referred to as ‘lost’ energy.

For example, if a modern boiler is 94% efficient, only 6% of energy is ‘lost’ as the boiler runs itself.

An old boiler may only have 60% efficiency – meaning 40% of the energy is ‘lost’ so you will pay more to heat your home as it takes more energy.

Like all modern domestic appliances, boilers have efficiency ratings of A to G – with A being the most effective at 90% or over.

Worcester Bosch’s top ten gas combi boilers

To help you make an informed choice, HomeSage have created a unique scoring system for each Worcester Bosch combi-boiler available in the UK.

Worcester Bosch currently manufacture 21 different gas combi boilers and we have based our rankings on:

• the energy efficiency rating,
• the length of warranty
• the output rate (kW),
• the flow rate, and
• the price.

The top ten Worcester Bosch gas combi boilers according to the HomeSage rankings are:

How does Worcester Bosch compare with other manufacturers?

Out of the top ten UK manufacturers, Worcester Bosch ranks third on the Trustpilot scoring table with an average score of 4.7 however they have the highest number of boilers available to choose from.

Our boiler reviews assess companies whose boilers are mostly gas powered so we’ve decided to include the Trustpilot reviews for our table because they are genuine, experience-based customers’ points of view.

Where two companies have the same average score, we’ve placed the company with a bigger range of boilers in the higher position.

What do customers on TrustPilot say about Worcester Bosch?

Happiness with the product

In general, Trustpilot customers are happy with their experience of Worcester Bosch boilers. With over 17,000 reviews and an average score of 4.7, this places them firmly in the ‘excellent’ category. 

Over 80% of customers rated their experience as ‘excellent’, 3% reviewed it as ‘average’, and 3% reviewed it as ‘bad’. Here is a small selection of recent customer reviews:

• Mr Elliott Hirst stated his Worcester Bosch boiler ‘required little work to install and has worked faultlessly since’ on 22^nd June 2020.

• Michael Waight reviewed that he was ‘really pleased with the Worcester Bosch boiler….and incredibly pleased with the company who installed it’ also on the 22^nd June 2020.

• Jamyhampshire stated that his ‘New boiler developed an operating fault six months after installation. As the boiler still operated, but with an intermittent large bang on starting it was not classed as an emergency and therefore was not repaired until two weeks after reporting the problem to Worcester Bosch’ on 8^th June 2020.

• Todd H reviewed that ‘The boiler is noisier than expected from a new unit. The bottom door has separated from the chassis. Apparently it’s a known issue that is easily replaced. But shows the quality of the parts. Haven’t had any serious issues needing repair’ on 8^th June 2020.

Both negative reviews received a follow up comment from Worcester Bosch including a customer helpline for the user to telephone for further assistance. 

The guarantee period and after-sales service

All Worcester Bosch boilers come with either a 6, 10- or 12-year guarantee, depending on the specific boiler. 

A guarantee is free and it means that the cost of repairs is covered for the specified length of time in case things go wrong. Worcester Bosch also offers a complimentary call out visit if your boiler develops a fault providing you can prove you get your boiler serviced yearly. 

Here are some recent Trustpilot reviews which refer to the customer after-sales service:

• M Showell reviewed ‘Disappointed that the timer was not covered as with the same Warranty as the boiler …the boiler packed up at 11 months..’ on 15^th June 2020.

• On the 17^th March 2020, Dave F. reviewed that ‘The 25i boiler is excellent but the service from Worcester Bosch is less than good. After almost a whole year I am still waiting for my guarantee. I am happy to report that within 10 minutes of my review I received my guarantee in email. Excellent service but just a pity I had to complain before I got what should have been sent 10 months ago. But thank you Worcester Bosch. You responded very quickly and have restored my faith in your company.’

• John Pattern reviewed ‘excellent service. Your engineer phoned before, as promised and he refused coffee! My old boiler is now quiet with no banging. Thank you’ on the 18^th June 2020.

• Roger Alexander stated he was happy with ‘Very good boiler and after sales’ on 8^th June 2020.

The best Worcester Bosch boilers

Below you’ll find our top boilers, split by power rating for your convenience.

• Small: up to 27kW
• Medium boilers: 28kW – 34kW
• Large boilers: 35kW and above

Worcester Bosch’s top 3 gas combi boilers up to 27kw

If you live in a smaller property, such as an apartment or a 1 or 2 bed terraced house with under 10 radiators, you are best choosing a 27kW boiler. These boilers are suitable if you have one bathroom in your property.

Worcester Bosch currently only have three very high-scoring boilers up to 27kw and here we score them in order of the HomeSage ranking.

Worcester Bosch 2000 25kw Boiler (91.89% HomeSage score)

The Worcester Bosch 2000 25kw Boiler is a suitable choice for a smaller property and has been designed to be affordable and reliable. 

It is sleek and modern-looking and can be wall mounted. It has a selection of flue lengths (the pipe that removes the wastewater vapour and gases) so you can install it at a location that works with your room design.

It comes in white and is 724mm x 400mm x 300mm in size – designed to fit in between standard kitchen cupboards if required. 

The Worcester 2000 is the quietest boiler in the range, and it comes with a five-year standard guarantee or six-year – if you choose to install with a Greenstar System Filter.

Worcester Bosch Greenstar 25i Boiler (91.41% HomeSage score)

The Worcester Bosch Greenstar 25i Boiler is well-suited to small or medium-sized properties and is their most popular combi boiler.

It has a digital display featuring a ‘quick info’ button which tells you your boiler status or diagnostic information at a glance. 

It has quick-set optimised heating and hot water temperatures for ease of use and comes with a pre-assembled wall-frame which makes installation (or replacement) quick and easy.

It is 330mm x 710mm x 400mm in size and comes in a white plastic finish. 

The Worcester Bosch Greenstar 25i Boiler provides you with clear information through its easy-to-use display, as well as having simple presets so you can set your hot water and heating to your exact requirements regularly. 

Worcester Bosch Greenstar 25Si Compact Boiler (91.16% HomeSage score)

The Worcester Bosch Greenstar 25Si Compact boiler is very similar to the Greenstar 25i, just slightly smaller as the name suggests.

The size of this boiler is 280mm x 690mm x 390mmm which means it can easily be tucked away in a kitchen cupboard out of sight. 

Much like the Greenstar 25i, the 25Si Compact boiler focuses on usability and it has a wide range of controls so you can get your heating and hot water just right whenever you need to.

It has frost protection technology so, even if you install it in a garage, you shouldn’t worry about frozen pipes. 

It is available in white with a flip down cover concealing the simple control knob panel. This boiler would be great in a small apartment or flat that is lacking in storage space. 

Worcester Bosch’s top 5 gas combi boilers (28-34kw)

If you live in a medium-sized terrace or semi-detached house with up to 4 bedrooms and 3 bathrooms, a boiler of 28-34kW is the choice for you. A 34kW boiler easily runs up to 15 radiators.

Of the 9 Worcester Bosch 28-34w combi boilers, here are the top 5 as ranked by HomeSage.

Worcester Bosch 2000 30kw Boiler (91.62% HomeSage score)

The Worcester Bosch 2000 30kW Boiler is very similar to the Worcester Bosch 2000 25kW boiler reviewed above but has a slightly higher output for those who have increased hot water needs. 

Much like the lower kW model, the Worcester Bosch 2000 30kw boiler has a modern look and digital control panel. It is available in white and is 724mm x 400mm x 300mm in size.

It has a flow rate of up to 12 litres per minute and it comes with a 5-year guarantee as standard – which can be increased to 6 years if you opt for the Greenstar System Filter.

There is a 10-year guarantee on the primary heat exchanger. 

This boiler is the quietest in the Worcester Bosch range and would work well in a small to average sized property who need a reliable boiler at an affordable price.

Worcester Bosch Greenstar 28CDi Compact Boiler (91.35% HomeSage score)

If you’re looking for a high output boiler that is compact enough to fit in a standard kitchen cupboard, the Worcester Bosch Greenstar 28CDi Compact boiler may be the best choice for you.

It would serve small, medium or larger properties that have up to two bathrooms.

Its diameters are 690mm x 390mm x 280mm and it comes in a classic white finish with a fold-down control cover.

This range of boilers have a clear focus on energy efficiency and the 28CDi achieves A+ ErP when installed alongside a smart internet connected Bosch EasyControl system so you have a minimum amount of ‘lost’ energy.

At the end of the boiler’s life, all parts of this system are 100% recyclable making it an environmentally friendly choice for consumers. 

Worcester Bosch Greenstar 30i Boiler (91.35% HomeSage score)

The Worcester Bosch Greenstar 30i would work well within a small, medium or large home and it’s part of the latest generation of lighter and smaller boilers from Worcester Bosch. 

It has a higher output than the 28CDi boiler as reviewed above, so suitable if you need slightly more hot water either for radiators or general use.

It has a standard control panel which has been designed to be clear and simple to use. This simplicity means it’s easier for you to diagnose any issues over the phone, so there is less chance you will need to pay to call out a plumber. 

The boiler itself has been designed to be accessed from the front making it easy for any part replacements to be installed quickly with no mess or fuss. 

It is 710mm x 400mm x 330mm in size so, much like the other compact boilers, it can be easily installed into a standard kitchen cupboard to minimize any disruption to your interior design scheme. 

Worcester Bosch Greenstar 32CDi Compact Boiler (91.16% HomeSage score)

As the name suggests, this is a compact boiler measuring in at 690mm x 390mm x 280mm – perfect to fit within a kitchen cupboard for minimal design disruption.

This boiler belongs to the Greenstar family so it has energy saving benefits. The 32CDi has an A-rated ErP of 92% and all of the parts of the boiler are 100% recyclable when it finally comes around to being replaced. 

Worcester Bosch Greenstar 32CDi Compact boiler is designed for semi-detached and detached houses with 3 to 4 bedrooms.

It can heat between 15 and 20 radiators with an output of 24kW. Its 32kW alongside over 10 l/min flow specification means it is capable of supplying hot water to more than one bathroom with no problems.

If you like the sound of this boiler but have less bathrooms to consider, try the Worcester Bosch Greenstar 28CDi Compact Boiler as reviewed above – the same style of boiler but with a smaller output. 

Worcester Bosch Greenstar 30Si Compact Boiler (91.08% HomeSage score)

This is a boiler is an ideal size for small to medium properties, as it has power to deliver but is compact in size.

A three-bedroom property with two bathrooms would be an ideal property for this boiler.

The Worcester Bosch Greenstar 30Si Compact boiler is classed as ‘green’ – meaning that it has an A grade energy efficiency rating and that using it is sure to reduce your home’s carbon footprint. 

It has a standard white finish with the fold-down control panel shield as all boilers in the Greenstar range have.

This boiler sizes in at 710mm x 400mm x 330mm making it slightly bigger than the 32CDi compact boiler. If you wanted to install this boiler inside a kitchen cabinet, it would be wise to measure up first!

This is a boiler suitable for heating 8-10 radiators so, if you have more radiators but would like a similarly energy efficient system, we would recommend the Worcester Bosch Greenstar 32CDi. 

Worcester Bosch’s top 5 gas combi boilers (35kw+)

Gas combi boilers of 35kW and higher work best in large semi-detached or detached homes.

To put this in perspective, a 42kW boiler will run up to 20 radiators and supply hot water for 3 or more bathrooms simultaneously.

Of the 9 Worcester Bosch 35kw combi boilers, here are the top 5 as ranked by HomeSage.

Worcester Bosch Greenstar 8000 Life 35kw Boiler (90.59% HomeSage score)

The Greenstar 8000 Life 35kw boiler is one of the models within the latest range from Worcester Bosch and it combines 50 years of award-winning innovation with sleek design and powerful technology.

The boiler is available in gloss black or gloss white so it packs an attractive, visual punch in any kitchen or utility room even when not concealed.

This boiler features a modern design and digital panel with push buttons to make controlling your home heating and water blissfully easy.

It is 780mm x 440mm x 365mm in size so, measurements permitting, it may fit within a standard kitchen unit but always check first.

One of the benefits of boilers in this range is the use of wireless connectivity with the Bosch EasyControl smart thermostat which allows you to control your hot water and heating wherever you are.

This boiler would be suitable for a medium sized home and would not have an issue heating water for 2 to 3 bathrooms.

Worcester Bosch Greenstar 36CDi Compact Boiler (90.45% HomeSage score)

Worcester Bosch Greenstar 36CDi Compact Boiler is fairly similar in output to the Greenstar 8000 Life 35kw boiler but is more compact in size (390mm x 680mm x 280mm) and not quite as stylish in aesthetic finish.

It would be suitable to heat a house of 4 bedrooms, up to 20 radiators, and 2 or more bathrooms.

It comes with the standard 5-year guarantee from Worcester Bosch should anything go awry. A 6 year warranty is available if you opt for a Greenstar System Filter.

Much like the other boilers in the Greenstar range, this boiler focuses on usability and clear, concise controls.

It has a fold-down cover for the control panel and should fit within your standard kitchen unit if required.

Worcester Bosch Greenstar 8000 Life 40kw Boiler (90.16% HomeSage score)

For a bigger property – or bigger hot water needs – than the previous boilers reviewed above, consider the Worcester Bosch Greenstar 8000 Life 40kw boiler.

With a 40kW output and a flow rate of 16.4 litres per minute, this is a boiler that will not struggle to heat a home with 4 bedrooms and 2 bathrooms even if you have a higher demand for hot water than usual. 

As with the rest of the boilers in this range, it is a stunning piece of equipment finished in gloss black or gloss white.

It measures in at 780mm x 440mm x 365mm and features a digital display panel with push buttons – and can be linked to smart devices to control your heating or hot water from anywhere.

Worcester Bosch Greenstar 8000 Style 35kw Boiler (90.16% HomeSage score)

Worcester Bosch Greenstar 8000 Style 35kw Boiler would be a solid choice for a boiler in a larger property requiring hot water for 2 to 3 bathrooms and with up to 20 radiators.

The size of this boiler is 780mm x 440mm x 365mm and the finish is gloss white or black for a luxe feel.

It’s a good looking piece of machinery so you may not want to hide this boiler away in your garage.

These boilers have a slightly higher flow rate than the Greenstar 36CDi Compact Boiler though they have a similar kW output.

Worcester Bosch Greenstar 8000 Style 40kw Boiler (90.16% HomeSage score)

This A-star rated boiler is a highly reliable system for large properties where there is a high demand for hot water and heating and when only the best will suffice.

Featuring a high gloss finish – available in both black or white – and a digital, full colour control panel with intuitive menu structure, the thermostat can be linked to your smartphone for control anywhere.

It also includes the first Greenstar intelligent filing system which makes sure the boiler maintains optimum pressure without the need to operate a filling link. This reduces the risk of callouts should something go wrong.

This boiler is 780mm x 440mm x 365mm in size – and presents as a top of the range boiler for semi-detached or detached homes of 3 bathrooms or more.

Save up to 54% on your new gas combi boiler

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Still unsure of what type of boiler, from what manufacturer, is best for you? Why not check out our other post on the best boilers in 2021 or the HomeSage Advice Hub for more info!