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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

On the PlumbProud quality scoring system, we rate this Worcester Bosch Greenstar Si Compact 25Si Combi boiler at 91.77%. To determine a boiler's quality, we consider many different factors from price installed to manufacturer guarantees, energy efficiency, likely cost of running, and more.

Fitted by an experienced Gas Safe PlumbProud engineer, the cost for this Worcester Bosch Greenstar Si Compact 25Si Combi boiler will be in the region of £2,100 on a standard, non-complicated installation.

To receive a free quote on the Worcester Bosch Greenstar Si Compact 25Si boiler, as well as professional advice on whether it will meet the needs of your home, simply enter your postcode in the quote box on this page, click here to email us, or call 01604 343053.


Installed price around

£2,100

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

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

The Worcester Bosch Greenstar Si Compact 25Si is a gas combi boiler.

Traditional boilers need one or more large tanks to work - one to heat and keep water warm for immediate use and the other to store water intended for heating later. Finding space for these large tanks is difficult in British residential property - remember that our houses and flats are among the smallest in the world. This is the problem that combi boilers were designed to solve when they were introduced in the 1970s.

Combi boilers don't need a tank - instead, they instantly heat water drawn from the mains using technology inside the boiler. This hot water is then distributed immediately to your taps or radiators on demand.

The biggest disadvantage to combi boilers is that they have a maximum capacity for heating water, meaning that they work best when only one point within a household wants hot water. For example, if someone is taking a shower and another person uses a hot water tap at the same time, the water pressure, volume and temperature to both points drops.

Should I install a Worcester Bosch Greenstar Si Compact 25Si combi boiler in my home?

Whether this Worcester Bosch Greenstar Si Compact 25Si Combi boiler is right for where you live depends on its size or "output" level. Size does not mean its physical dimensions - it means how powerful it is.

The output level of a boiler tells you how much power it has to heat the water coming from your taps and warming up your radiators. The higher the output level, the greater the volume of water it can heat up.

If the output (measured in kilowatts) is too high, you'll pay higher gas bills and your water will be piping hot. Too low and the water coming out of your taps and being fed into your radiators will often be lukewarm.

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 experienced heating engineers would likely recommend that, at this level of output, this Worcester Bosch Greenstar Si Compact 25Si Combi boiler would be a suitable choice for smaller homes and apartments with up to 10 radiators and one bathroom.

With all combi boilers, the "flow rate" (measured in litres per minute) is as important a consideration as output rate when choosing which model to go for. This Worcester Bosch Greenstar Si Compact 25Si Combi boiler's flow rate is 10 L/m.

Like all combi boilers, the Worcester Bosch Greenstar Si Compact 25Si draws water from the mains. It instantly heats that water and then distributes it to the parts of your home which need it - taps, radiators, bathrooms, and so on.

However, the water in the mains pipe that feeds your boilers has its own flow rate - normally between 10 and 12l/m. So if you choose a combi with a flow rate of 14l/m but local water pressure is equivalent to 11l/m, your boiler will actually operate at 11l/m - below its capacity.

In addition, if different family members want hot water at the same time (like for regular morning and evening showers) and your boiler has to provide hot water to your radiators at the same time, a combi boiler may not be suitable.

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.


The size of the Worcester Bosch Greenstar Si Compact 25Si

The measurements of the Worcester Bosch Greenstar Si Compact 25Si are 690 mm by 390 mm by 280 mm.

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

Condensing boilers like the Worcester Bosch Greenstar Si Compact 25Si improve energy efficiency and reduce your annual expenditure on gas.

They do this by capturing and recycling the warmth still present in water vapour condensation and flue exhaust gases to, for example, increase the temperature of the colder water returning from your radiators.

Condensing boilers are also much better for the environment because they emit fewer greenhouse gases.

Is the combi Worcester Bosch Greenstar Si Compact 25Si boiler energy efficient?

With growing concern among the public about accelerating climate change, how we heat our homes and the impact this has on the environment has become a major topic of concern for many homeowners.

About 14% of the greenhouse gases we produce in the UK come from the power needed for central heating. In bigger British cities, gas boilers are a significant source of nitrogen dioxide emissions.

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.

All boilers manufactured in the UK from April 2018 must achieve a SEDBUK “A” grade and an energy efficiency rating of 92% or above. Before that, the minimum was 88% - efficiency ratings of 88% and 89% were scored a “B” and 90%+ an "A".

A boiler's energy efficiency rating describes how much energy it uses and wastes during its standard operation.

The energy efficiency of the Worcester Bosch Greenstar Si Compact 25Si was rated at 90.5% with a SEDBUK grading of "A".

The Energy Related Products (ERP) Directive is a European directive which applies to all products that consume energy over their lifetime.

It encourages companies to create products that are environmentally friendlier at all life cycle stages, including initial manufacturing and end use through to final disposal, with the aim of reducing harmful gas emissions.

The Worcester Bosch Greenstar Si Compact 25Si is rated "A" for heat and "A" for water.

How long am I covered by the warranty for if the Worcester Bosch Greenstar Si Compact 25Si breaks down?

Worcester Bosch offers a parts and labour warranty of 7 years on the Worcester Bosch Greenstar Si Compact 25Si.


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 Combi Gas boiler

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

Using factors such as price installed, manufacturer guarantees, energy efficiency and the likely cost of running, among others, this model has been rated as scoring 91.77% on the PlumbProud boiler benchmarking system.

This Worcester Bosch Greenstar Si Compact 25Si Combi boiler will cost around £2,100 fitted through PlumbProud where there are no complications during the installation.

To contact us, please enter your postcode in the quote boxes on this page, click here to email us, or give us a call on 01604 343053. We can provide you with a free quote on the Worcester Bosch Greenstar Si Compact 25Si boiler and offer professional advice and guidance on whether this Worcester Bosch Greenstar Si Compact 25Si Combi boiler is the right choice for your home.


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 combi, system or regular boiler?

The Worcester Bosch Greenstar Si Compact 25Si boiler is an option you may wish to consider if you're looking for a combi boiler for your house or flat.

Combi boilers have much to recommend them - not least the fact that they save a lot of space. Combination (or combi) boilers were introduced by manufacturers in the 1970s to provide practical central heating and hot water distribution to smaller properties - remember that UK houses and flats tend to be among the smallest in the developed world.

Traditional boilers require one or more storage tanks to keep hot water warm and to store water for heating later. In contrast, combi boilers draw water directly from the mains supply and heat it instantly, removing the need for a storage tank. The heated water is then distributed to your taps and radiators on demand.

While combi boilers are suitable choices for many properties, especially those without a loft, there is also a disadvantage in using them. Water is heated instantly and the volume of water that can be heated at any one time is limited. This can result in less water being sent to taps and showers if more than one is being used simultaneously. In these instances, the water pressure to both points will drop.

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

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

Output measures in kilowatts how much power a boiler can use when heating water for your radiators or taps. The higher the output rate, the more water it can heat.

If the output rate is too low, your hot water might often be only lukewarm, and if it is too high, you will be paying more for your gas than you need to.

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

Most Gas Safe boiler installers would recommend that this Worcester Bosch Greenstar Si Compact 25Si Combi boiler would be suitable for smaller homes and apartments with up to 10 radiators and one bathroom.

If you are thinking about installing a combi boiler like the Worcester Bosch Greenstar Si Compact 25Si in your home, you should consider flow rates as well as output rates. This Worcester Bosch Greenstar Si Compact 25Si Combi boiler's flow rate is 10 L/m.

The flow rate indicates the maximum volume of water (measured in litres per minute) that your boiler can heat up and send to your radiators, taps and showers at any one time. The more taps and showers that could be in use simultaneously or the greater the number of radiators you have, the higher the flow rate you need.

However, you should establish what the mains pressure is at your property as a combi boiler can only heat the water that comes into your home.

For example, if your mains pressure is 12 litres per minute, your boiler can only heat and distribute hot water at a rate of 12 litres per minute even if it has a higher flow rate capacity. Typically, a power shower will require 10 litres of water per minute.

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 large is the Worcester Bosch Greenstar Si Compact 25Si?

The Worcester Bosch Greenstar Si Compact 25Si has the following dimensions - 690 mm high, 390 mm wide, and 280 mm deep.

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

The Worcester Bosch Greenstar Si Compact 25Si is a condensing gas boiler - where possible, we always recommend to clients that they choose one of the very latest condensing boilers to take advantage of this technology, which improves year after year.

Condensing boilers are more energy-efficient as they capture and recycle the heat contained in flue exhaust gases and water vapour condensation. They then use this heat to perform tasks like warming up colder water returning to the boiler from the radiators.

By choosing a condensing boiler, you'll help the environment as well as save money on your gas bills.

How energy efficient is the Worcester Bosch Greenstar Si Compact 25Si combi?

Concern for the environment is causing more and more homeowners to think about how they heat their homes and its impact on climate change.

As much as 14% of the UK’s greenhouse gas production derives from our domestic central heating systems. Gas boilers are responsible for dangerous levels of nitrogen dioxide emissions in Britain's largest cities.

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.

An energy efficiency rating of 92% or above is a legal requirement for all boilers manufactured and installed in the UK today. 92% is equivalent to a low-to-middle "A" grade on the "Seasonal Efficiency of Domestic Boilers" (SEDBUK) scale.

Energy efficiency measures how much energy a boiler uses and wastes in the course of its normal operation. The lower the waste, the lower your gas bills.

The Worcester Bosch Greenstar Si Compact 25Si was awarded an efficiency rating of "90.5%", equivalent to a "A" rating on the SEDBUK system.

Energy-efficient boilers help the environment as they require less fuel and emit fewer harmful gases. In 2015, the EU introduced the Energy Related Products Directive (ERP), the aim of which was to ensure that all manufacturers, including boiler manufacturers, developed more efficient products and processes.

The legislation aims to conserve energy at all life cycle stages from initial production to actual use by the customer, through to the point of disposal.

The Worcester Bosch Greenstar Si Compact 25Si has been given an ERP rating of "A" for heat and "A" for water.

If the Worcester Bosch Greenstar Si Compact 25Si breaks down, will I be covered by the warranty?

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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