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Worcester Bosch Greenstar Si Compact 25Si boiler

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Plumbproud rating

91.77%

Worcester Bosch Greenstar Si Compact 25Si Combi Gas boiler

This Worcester Bosch Greenstar Si Compact 25Si Combi boiler scores 91.77% on our PlumbProud boiler quality benchmark tests. To determine our rating, we consider many factors, such as the cost of installation, manufacturer guarantees, energy efficiency, and likely running costs.

Expect this Worcester Bosch Greenstar Si Compact 25Si Combi boiler to cost you £2,100 fully installed where there are no complications on the fit if you choose PlumbProud for this installation.

We recommend that you speak to our friendly advisors by calling 01604 343053 to seek professional advice on whether the Worcester Bosch Greenstar Si Compact 25Si boiler is right for your home. Our team can also provide you with a free quotation for this Worcester Bosch Greenstar Si Compact 25Si Combi boiler. Alternatively, click here to email us or enter your postcode into the quotation box on this page.


Installed price around

£2,100

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Worcester Bosch Greenstar Si Compact 25Si Combi Gas boiler frequently asked questions

Is the Worcester Bosch Greenstar Si Compact 25Si a combi boiler, system boiler or regular boiler?

Suitable for a house or a flat, the Worcester Bosch Greenstar Si Compact 25Si combi boiler is worth considering if you want a combi boiler.

Combination or combi boilers are highly efficient and save a lot of space in your home. Combi boilers heat water directly from the mains when you turn on a tap and, as a result, you don’t need a hot water storage cylinder or a cold water tank in the roof space.

These boilers are, therefore, suitable for smaller homes and especially those without a loft. They are also cost-effective as the water is heated instantly and distributed on demand rather than being stored. Combi boilers are the most popular type of boilers in the UK and replacing an older boiler with a new combi boiler will reduce your gas bills significantly.

However, there are downsides to this type of boiler. If you take a shower while someone else is using a tap, less water will reach each point of usage at lower rates of pressure and temperatures as combi boilers can only heat a certain volume of water at any given time.

Is the Worcester Bosch Greenstar Si Compact 25Si combi boiler the right choice for my house or apartment?

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 Si Compact 25Si combi has an output of 25 kW, so which types of property would this Worcester Bosch Greenstar Si Compact 25Si Combi boiler be appropriate for?

A PlumbProud heating engineer would recommend that this Worcester Bosch Greenstar Si Compact 25Si Combi boiler is suitable for smaller homes and apartments with up to 10 radiators and one bathroom.

You'll also need to be sure to choose a combi boiler with the right flow rate for your home.

The flow rate indicates the maximum volume of hot water (measured in litres per minute) that your boiler can distribute at any given time. This means that if you and your family are likely to be using several taps and showers simultaneously or you have a lot of radiators, you need a boiler with a high flow rate. This Worcester Bosch Greenstar Si Compact 25Si Combi boiler's flow rate is 10 L/m.

As with all combi boilers, the Worcester Bosch Greenstar Si Compact 25Si is only able to heat and distribute water at the rate at which it actually enters your property.

For this reason, you shouldn't purchase a boiler with a very high flow rate if the flow rate in your mains pipes is lower because the extra capacity doesn't mean it can draw more water from the mains pipes.

When our engineer comes out to quote you, they may recommend that you choose a heat only boiler or system boiler instead if your family's demand for hot water is higher than normal.


Worcester Bosch Greenstar Si Compact 25Si - size in millimetres

The dimensions of the Worcester Bosch Greenstar Si Compact 25Si are 690 mm tall, 390 mm wide, and 280 mm deep.

Is the Worcester Bosch Greenstar Si Compact 25Si a non-condensing or condensing boiler?

The Worcester Bosch Greenstar Si Compact 25Si 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 Si Compact 25Si combi boiler rated as environmentally friendly?

More and more homeowners are aware of the importance of how we heat our homes and its impact on climate change and other environmental issues.

Nitrogen dioxide emissions in Britain's largest cities are at dangerous levels and this has been caused by gas boilers. In fact, 14% of the UK’s greenhouse gases are produced by central heating.

If you decide to install a Worcester Bosch Greenstar Si Compact 25Si combi in your home, will you be helping the environment with your choice? Let’s have a look at the figures.

Boilers manufactured and installed in the UK are assigned energy efficiency ratings following testing to an agreed set of standards. These scores indicate how much energy the boiler uses and how much goes to waste when it's in operation.

By law, boilers must achieve a SEDBUK rating of "A" subject to achieving a minimum of 92% energy efficiency. Prior to April 2018, the minimum was 88% (88% and 89% on the SEDBUK are graded "B" and 90% and above is graded "A").

The Worcester Bosch Greenstar Si Compact 25Si was awarded an efficiency rating of 90.5% with a SEDBUK band rating of "A".

The Energy Related Products (ERP) directive is Europe-wide legislation designed to reduce harmful gas emissions at all points of a product's life cycle - from the production process to its actual end use, right through to final disposal.

The Worcester Bosch Greenstar Si Compact 25Si has a rating of "A" for heat and "A" for water.

What is the warranty period on a Worcester Bosch Greenstar Si Compact 25Si combi boiler?

Parts and labour charges incurred during a repair on the Worcester Bosch Worcester Bosch Greenstar Si Compact 25Si boiler are covered by a 7 year warranty.


Worcester Bosch Greenstar Si Compact 25Si Gas Combi boiler specifications

Powered by GasGas
LocationExternal
Condensing?Yes
Efficiency rating90.5%
Band ratingA
LPG Compatible?Yes
P/L Warranty7 Years
Output in kW25 kW
Height690 mm
Width390 mm
Depth280 mm
MountingWall
Flow rate10 L/m
ERP HeatA
ERP WaterA

The top 10 rated Gas Combi boilers

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

1Vaillant ecoTEC Plus 82593.35%
2Vaillant ecoTEC Plus 83292.98%
3Worcester Bosch Greenstar 2000 25kW92.89%
4Viessmann Vitodens 050-W 29kW92.66%
5Vaillant ecoTEC Plus 83592.60%
6Worcester Bosch Greenstar CDi Compact 2892.57%
7Vaillant ecoFIT Pure 82592.39%
8Vaillant ecoTEC Plus 83892.16%
9Vaillant ecoTEC Exclusive IQ 83591.90%
10Vaillant ecoTEC Pro 2491.77%

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Worcester Bosch Greenstar Si Compact 25Si boiler

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Worcester Bosch Greenstar Si Compact 25Si Combi Gas boiler

  1. Home
  2. Worcester Bosch Greenstar Si Compact 25Si
Plumbproud rating for this boiler
91.77%

This Worcester Bosch Greenstar Si Compact 25Si Combi boiler has been rated at 91.77%. Our PlumbProud boiler quality rating system uses price installed, energy efficiency, likely running costs, the manufacturer's warranty and other factors to determine the rating we give.

You should budget around £2,100 for the supply and installation of this Worcester Bosch Greenstar Si Compact 25Si Combi boiler by PlumbProud.

You can speak to our friendly and professional advisors by calling 01604 343053. They can provide you with a free quotation on the Worcester Bosch Greenstar Si Compact 25Si boiler and confirm that it is suitable for your home. You can also click here to email us or enter your postcode into the quotation box on this page.


Installed price guideline
£2,100

Get your free quote

Worcester Bosch Greenstar Si Compact 25Si Gas Combi boiler specifications

Powered by GasGas
LocationExternal
Condensing?Yes
Efficiency rating90.5%
Band ratingA
LPG Compatible?Yes
P/L Warranty7 Years
Output in kW25 kW
Height690 mm
Width390 mm
Depth280 mm
MountingWall
Flow rate10 L/m
ERP HeatA
ERP WaterA

Worcester Bosch Greenstar Si Compact 25Si Combi Gas boiler frequently asked questions

Is the Worcester Bosch Greenstar Si Compact 25Si a system boiler, a combi boiler or a regular boiler?

You might want to consider the Worcester Bosch Greenstar Si Compact 25Si for your house or flat if you are looking for a combi boiler.

Combi boilers were introduced by manufacturers in the 1970s to offer British homeowners a way to cheaply and reliably heat their homes and have hot water without taking up too much space. Previously, most boilers had one or more storage tanks, which either heated water and kept it warm or held water to be heated later.

With combi boilers, there is no need to find space for large tanks around your home as the hot water needed for your radiators and taps is available on demand. Combi boilers do this by drawing water from your mains supply, heating it instantly whenever you need it and then distributing it to where it's needed in the home.

The major disadvantage to combi boilers is that they have a maximum capacity for heating water. In a larger household, water pressure, volume and temperature will drop if two or more people are trying to use hot water at the same time.

Is a Worcester Bosch Greenstar Si Compact 25Si combi boiler suitable for my house or apartment?

You should make sure that the boiler you choose for your property is the right "size". And size doesn't mean its physical dimensions. Size means how much power it has - the "output".

A boiler's output level measures how much power it can use to provide you with the hot water you need for your radiators and taps. If a boiler has a high output rate, it can heat greater volumes of water.

If you choose a boiler with too low an output, you'll find that the water coming out of your taps and in your radiators won't be as hot as you want it to be. Choosing one whose output is too high means you'll pay more than you need to for the gas your boiler needs to work.

The Worcester Bosch Greenstar Si Compact 25Si combi outputs at a maximum of 25 kW, so which types of property would this Worcester Bosch Greenstar Si Compact 25Si Combi boiler be appropriate for?

Most heating engineers would suggest that the Worcester Bosch Greenstar Si Compact 25Si combi boiler would be a suitable choice for installation in smaller homes and apartments with up to 10 radiators and one bathroom.

You need to consider the flow rate as well as the output rate when choosing a combi boiler.

Flow rates, measured in litres per minute, indicate how much water your boiler can heat and distribute around your home at any given time. If your family regularly use hot water around the house at the same time and you have a lot of radiators, you should choose a boiler with a high flow rate. This Worcester Bosch Greenstar Si Compact 25Si Combi boiler's flow rate is 10 L/m.

However, you also need to consider the flow rate of your local mains water supply. Combis can only draw water from the mains as fast as the pipes can deliver it. If you choose a boiler with a 14l/m flow rate and the mains pipes into your home have a flow rate of 12l/m, your boiler won't be able to operate at full capacity. In other words, try to make sure the local water pressure and your boiler flow rates are as close as possible.

When our engineer comes out to quote you, they may recommend that you choose a heat only boiler or system boiler instead if your family's demand for hot water is higher than normal.


How big is the Worcester Bosch Greenstar Si Compact 25Si?

The dimensions of the Worcester Bosch Greenstar Si Compact 25Si are 690 mm tall, 390 mm wide, and 280 mm deep.

Is the Worcester Bosch Greenstar Si Compact 25Si condensing or non-condensing?

We always recommend to clients that they select the very latest condensing boiler for their home.

Condensing boilers like the Worcester Bosch Greenstar Si Compact 25Si are more efficient with the gas they use in operation, meaning that you'll benefit from lower fuel bills. Condensing boilers are also better for the environment.

They achieve their efficiency by capturing and recycling the heat still present in the water vapour condensation and flue exhaust gases created when a boiler burns gas to get the energy it needs. It then reuses that recycled heat to perform a number of tasks, including heating the colder water that comes back to your boiler via the radiator.

Is the Worcester Bosch Greenstar Si Compact 25Si combi boiler rated as environmentally friendly?

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.

Gas boilers are responsible for dangerous atmospheric levels of nitrogen dioxide emissions in Britain's biggest cities and, overall, 14% of the UK’s greenhouse gases are produced by our domestic central heating systems.

Would choosing the Worcester Bosch Greenstar Si Compact 25Si combi boiler be an environmentally friendly decision? Here's what the figures say.

All boilers manufactured and supplied in the UK must achieve an energy efficiency rating of at least 92% (an "A" SEDBUK grade). This is higher than the previous 88%, which was a legal requirement prior to April 2018.

The energy efficiency rating is used to work out how much energy a boiler both uses and wastes when it's switched on and working correctly - its standard functioning and operation.

The Worcester Bosch Greenstar Si Compact 25Si is rated as 90.5% energy efficient, equivalent to a "A" SEDBUK rating.

The ERP (Energy Related Products Directive) applies to all products that consume energy at any time in their lifetime, from manufacture to disposal and all points in between.

This European legislation intends to encourage manufacturers to offer end users products that are better for the environment through the creation of fewer harmful gas emissions at all points of a product's life cycle.

The ERP rating for the Worcester Bosch Greenstar Si Compact 25Si is "A" for heat and "A" for water.

How long is the warranty period on a Worcester Bosch Greenstar Si Compact 25Si combi boiler?

The Worcester Bosch Greenstar Si Compact 25Si is covered by a parts and labour warranty of 7 years following installation.


The top 10 rated Gas Combi boilers

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

1Vaillant ecoTEC Plus 82593.35%
2Vaillant ecoTEC Plus 83292.98%
3Worcester Bosch Greenstar 2000 25kW92.89%
4Viessmann Vitodens 050-W 29kW92.66%
5Vaillant ecoTEC Plus 83592.60%
6Worcester Bosch Greenstar CDi Compact 2892.57%
7Vaillant ecoFIT Pure 82592.39%
8Vaillant ecoTEC Plus 83892.16%
9Vaillant ecoTEC Exclusive IQ 83591.90%
10Vaillant ecoTEC Pro 2491.77%
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