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Worcester Bosch Greenstar I System 21i boiler

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Plumbproud rating

90.84%

Worcester Bosch Greenstar i System 21i System Gas boiler

We have awarded this Worcester Bosch Greenstar i System 21i System boiler a rating of 90.84% in our boiler quality benchmark tests. To determine a score for each boiler, we factor in several different points of comparison including energy efficiency, manufacturer guarantees, estimated running costs, price and more.

You should budget around £2,200 for the supply and installation of this Worcester Bosch Greenstar i System 21i System boiler by PlumbProud.

To receive a free quote on the Worcester Bosch Greenstar I System 21i and to get professional guidance and advice on whether this Worcester Bosch Greenstar i System 21i System boiler is the right choice for your home, please call us on 01604 343053, enter your postcode in the quote boxes on this page, or click here to email us.


Installed price around

£2,200

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Worcester Bosch Greenstar i System 21i System Gas boiler frequently asked questions

Is the Worcester Bosch Greenstar I System 21i boiler a combi, regular or a system boiler?

Worcester Bosch’s Greenstar I System 21i is one you might consider if you’re looking for a system boiler for your house or flat.

System boilers need a hot water cylinder to work - normally fitted inside an airing or landing cupboard or similar spot. Unlike heat only boilers, they do not require a separate cold water tank, making them a more suitable choice if you have no loft, lack space in the attic, or are planning to do a loft conversion.

These boilers distribute hot water around your home to your taps and radiators using (often built-in) circulating pumps and they're easier to install as there is one less component (the water tank) to find room for. A system boiler needs to be programmed to tell it what times you want heat and hot water - unlike combi boilers, they don't provide hot water on demand.

Is the Worcester Bosch Greenstar I System 21i system boiler a suitable choice for my property?

Selecting the right boiler for your home means choosing a boiler that is the right size. And, by size, we don't mean how big it is, we mean how powerful it is - the "output".

Your boiler’s output is a measurement of the power it has available to it to heat the water you need for your radiators or for when you turn on a tap, bath or shower. A higher output rate means it has more power and can heat more water.

It's important to choose an output that matches the demand for water in your home because if your boiler has too low an output, you'll often find only lukewarm water comes out of your taps or heats your radiators. If it’s too high, you’ll be paying more for your gas than you need to.

The Worcester Bosch Greenstar I System 21i system has an output of 21 kW, so which types of property would this Worcester Bosch Greenstar i System 21i System boiler be appropriate for?

Most experienced Gas Safe boiler installers would recommend that a boiler with this output level would be most suitable for medium-sized homes and larger apartments with 10-15 radiators and two bathrooms.


What size is a Worcester Bosch Greenstar I System 21i boiler?

The size of the Worcester Bosch Greenstar I System 21i boiler is 710 mm high, 400 mm wide, and 330 mm deep.

Greenstar I System 21i – non-condensing or condensing?

We recommend the Worcester Bosch Greenstar I System 21i as it is a modern condensing gas boiler from a trusted manufacturer with a reputation for supplying highly energy-efficient boilers.

Condensing boilers capture the heat still present in water vapour condensation and flue exhaust gases and recycle it back into the heating system. With this extra energy, your boiler can, among other tasks, reheat colder water coming back from your radiators without having to burn more gas.

Condensing boilers significantly reduce your quarterly gas costs and they're better for the environment.

Is choosing the Worcester Bosch Greenstar I System 21i system boiler environmentally friendly?

How we heat our homes and the effect that has on climate change has become important to many homeowners worried about the environment.

In Britain's bigger cities, gas boilers, in particular, are responsible for dangerous levels of nitrogen dioxide emissions. Overall, 14% of all of the UK’s greenhouse gas production comes from heating our homes.

Would installing a Worcester Bosch Greenstar I System 21i system boiler in your home help combat climate change? What do the figures suggest?

In the UK, by law, all boilers manufactured since April 2018 must have a SEDBUK “A” rating and operate to a minimum level of 92% energy efficiency. Prior to this, the minimum was 88% – 88/89% would score a "B" and 90% or more an "A" on the SEDBUK scale.

The energy efficiency rating measures the amount of energy a boiler consumes when it's in use and how much it loses on non-core operations.

Following testing, the Worcester Bosch Greenstar I System 21i was given an efficiency rating of 94% and a SEDBUK grading of "A".

The ERP (or Energy Related Products Directive) is European legislation which applies to all products that consume energy throughout their lifetime.

Its purpose is to encourage manufacturers to offer products that are kinder to the environment by reducing harmful gas emissions at all stages, from production and end use right through to disposal.

The ERP rating for the Worcester Bosch Greenstar I System 21i is "A".

How many years' warranty does the Worcester Bosch Greenstar I System 21i system come with?

The Worcester Bosch Greenstar I System 21i boiler comes with a parts and labour warranty of 7 years.


Worcester Bosch Greenstar i System 21i Gas System boiler specifications

Powered by GasGas
LocationExternal
Condensing?Yes
Efficiency rating94%
Band ratingA
LPG Compatible?Yes
P/L Warranty7 Years
Output in kW21 kW
Height710 mm
Width400 mm
Depth330 mm
MountingWall
ERP HeatA

The top 10 rated Gas System boilers

Using the Plumbproud scoring system, the current 10 ten Gas System boilers assessed using a number of important variables are as follows:

1Vaillant ecoTEC Plus 61295.72%
2Vaillant ecoTEC Plus 61595.20%
3Vaillant ecoTEC Plus 61894.37%
4Vaillant ecoTEC Plus 62493.33%
5Worcester Bosch Greenstar i System 9i92.89%
6Vaillant ecoTEC Plus 63092.75%
7Worcester Bosch Greenstar 4000 12kW92.50%
8Vaillant ecoTEC Exclusive IQ 62792.42%
9Vaillant ecoFIT Pure 61292.38%
10Vaillant ecoFIT Pure 61592.36%

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Worcester Bosch Greenstar i System 21i System Gas boiler

  1. Home
  2. Worcester Bosch Greenstar i System 21i
Plumbproud rating for this boiler
90.84%

According to our PlumbProud boiler quality scoring system, we rate this model 90.84%. We rank boilers using a number of different factors including price installed, manufacturer guarantees, energy efficiency, likely running costs, and more.

On a standard fit, we would expect this Worcester Bosch Greenstar i System 21i System boiler to cost you £2,200 supplied and fully installed by an experienced Gas Safe PlumbProud fitter.

If you would like to get in touch with us for a free quote and professional guidance and advice on whether the Worcester Bosch Greenstar I System 21i is the right choice for your home, you can do so by entering your postcode in the quote boxes on this page, calling us on 01604 343053 or you can click here to email us.


Installed price guideline
£2,200

Get your free quote

Worcester Bosch Greenstar i System 21i Gas System boiler specifications

Powered by GasGas
LocationExternal
Condensing?Yes
Efficiency rating94%
Band ratingA
LPG Compatible?Yes
P/L Warranty7 Years
Output in kW21 kW
Height710 mm
Width400 mm
Depth330 mm
MountingWall
ERP HeatA

Worcester Bosch Greenstar i System 21i System Gas boiler frequently asked questions

Worcester Bosch Greenstar I System 21i - combi, system or regular boiler?

The Worcester Bosch Greenstar I System 21i is a gas system boiler.

System boilers are suitable for homes with a higher-than-average demand for central heating and water - for example, larger homes and larger families.

Tell the boiler when you want hot water using the control panel - it draws water from the mains, heats it and keeps it warm throughout the day in the hot water cylinder. As long as you remember to tell the boiler when you want hot water, you have a big enough cylinder, and there's not an unusually high demand for water on a particular day, you should have hot water whenever you need it.

System boilers do not require a cold water storage tank either, unlike heat only boilers, meaning they're cheaper, quicker and easier to install.

Is a Worcester Bosch Greenstar I System 21i system a suitable choice for my house or flat?

You should make sure that the boiler you install in your property is the right "size". And, by size, we don't mean how big it is, we mean how powerful it is - the "output".

Your boiler has to be powerful enough to heat all the hot water you need for your radiators and taps. Power is measured in kilowatts and the more kilowatts a boiler has available to it, the more water it can heat.

If the output (measured in kilowatts) is too high, you'll have all the power you need and more but your gas bills will be much higher. If it's too low, you'll often find that the water coming out of your taps and fed into your radiators is only lukewarm.

With the Worcester Bosch Greenstar I System 21i system's output at 21 kW, which types of property would this Worcester Bosch Greenstar i System 21i System boiler be most appropriate for?

Most experienced Gas Safe boiler installers would recommend that a boiler with this output level would be most suitable for medium-sized homes and larger apartments with 10-15 radiators and two bathrooms.


Dimensions of the Worcester Bosch Greenstar I System 21i boiler

The Worcester Bosch Greenstar I System 21i's dimensions are 710 mm [H] x 400 mm [W] x 330 mm [D].

Is the Worcester Bosch Greenstar I System 21i condensing or non-condensing?

The Worcester Bosch Greenstar I System 21i is a condensing boiler – we recommend to all clients that they choose the very latest condensing boilers because their efficiency continues to improve year after year.

Condensing boilers recycle heat from both water vapour condensation and flue exhaust gases via a secondary heat exchanger. With this heat, it performs other tasks like warming up colder water returning from your radiator without having to use more gas.

You will save money on your gas bills every year by choosing a condensing boiler as well as benefitting the environment.

Is the Worcester Bosch Greenstar I System 21i system an environmentally friendly boiler?

As more of us are increasingly concerned about climate change, how we heat our homes and its impact on the environment has become an issue of importance to homeowners.

With central heating being responsible for 14% of greenhouse gas emissions in the UK, your choice of boiler matters. Gas boilers are also responsible for the significant atmospheric volumes of dangerous nitrogen dioxide emissions in larger British cities.

Will choosing to install a Worcester Bosch Greenstar I System 21i system in your home help the environment? Let's review the figures.

All boilers manufactured and installed in the UK are required to have an energy efficiency rating of 92% or above (or a good “A” SEDBUK rating). Before April 2018, when the law changed, the minimum energy efficiency level permissible was 88% (86-90% is a SEDBUK "B" rating and 90%+ is an "A" rating).

A boiler's energy efficiency rating indicates the amount of energy used and wasted during normal operational performance.

Following its assessment, the Worcester Bosch Greenstar I System 21i was given an efficiency rating of 94% and a SEDBUK grading of "A".

The Energy Related Products Directive grades products according to the energy they consume and the harmful gas emissions they create, from manufacturing right through to final disposal, including how they're used by customers between these two points.

The Worcester Bosch Greenstar I System 21i is rated "A".

What warranty does the Worcester Bosch Greenstar I System 21i system boiler come with?

Worcester Bosch offers a parts and labour warranty of 7 years on the Worcester Bosch Greenstar I System 21i.


The top 10 rated Gas System boilers

Using the Plumbproud scoring system, the current 10 ten Gas System boilers assessed using a number of important variables are as follows:

1Vaillant ecoTEC Plus 61295.72%
2Vaillant ecoTEC Plus 61595.20%
3Vaillant ecoTEC Plus 61894.37%
4Vaillant ecoTEC Plus 62493.33%
5Worcester Bosch Greenstar i System 9i92.89%
6Vaillant ecoTEC Plus 63092.75%
7Worcester Bosch Greenstar 4000 12kW92.50%
8Vaillant ecoTEC Exclusive IQ 62792.42%
9Vaillant ecoFIT Pure 61292.38%
10Vaillant ecoFIT Pure 61592.36%
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