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Worcester Bosch Greenstar 4000 25kW boiler

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  2. Worcester Bosch Greenstar 4000 25kW
Plumbproud rating

91.41%

Worcester Bosch Greenstar 4000 25kW Combi Gas boiler

Our PlumbProud quality scoring system considers important factors like energy efficiency, the length of a manufacturer’s guarantee, likely running costs, and installed price to determine a boiler's value for money. This model has received 91.41% from our engineers.

This Worcester Bosch Greenstar 4000 25kW Combi boiler will cost approximately £2,100 supplied and fully installed through PlumbProud assuming that there are no unexpected complications during the fitting.

Please enter your postcode in the quote boxes on this page, email us, or call us on 01604 343053 to get a free quote and guidance on whether the Worcester Bosch Greenstar 4000 25kW boiler is the right choice for your home.


Installed price around

£2,100

GET A COMPETITIVE BOILER QUOTE

Please enter your postcode below to get a personalised quotation for the perfect boiler for your home

Worcester Bosch Greenstar 4000 25kW Combi Gas boiler frequently asked questions

Worcester Bosch Greenstar 4000 25kW - a system boiler, regular boiler or combi boiler?

You might want to consider the Worcester Bosch Greenstar 4000 25kW for your house or flat if you are looking for a combi boiler.

The UK has some of the smallest homes in the Western world, which is partly why combi boilers were introduced in the 1970s. Traditional boilers require one or more large storage tanks which they use to either heat water and keep it warm or store water intended for heating later. These tanks took up a lot of space in people's homes.

Combi boilers save space because they don't require these tanks to operate. Instead, combis draw water direct from your mains supply then instantly heat and distribute it on demand.

The biggest disadvantage in using combi boilers is that they have a maximum capacity volume for heating water. While this may not be an issue in a small household, it could be for a larger household where there is higher demand for hot water. When more than one person is using the water, it is distributed between the two points, reducing the pressure and temperature at each point.

Would the Worcester Bosch Greenstar 4000 25kW combi boiler be suitable for my house or flat?

It's best to choose a boiler whose size or "output" is right for your property. With boilers, however, size does not mean how big a boiler is, it means how much power it has.

A boiler’s output indicates the amount of power it can use when heating the water which it then sends to your taps and radiators. The higher the output rate, the more water it can heat.

If a boiler’s output is too low, there will be times when your hot water might not be as hot as you want it to be. If it is too high, you’ll likely be paying more than you need to for your gas.

Measured in kilowatts, the Worcester Bosch Greenstar 4000 25kW combi's output level is 25 kW, so which types of property would this Worcester Bosch Greenstar 4000 25kW Combi boiler be an appropriate choice for?

Most Gas Safe boiler installers would recommend that this Worcester Bosch Greenstar 4000 25kW Combi boiler would be suitable for smaller homes and apartments with up to 10 radiators and one bathroom.

Flow rates are important when choosing a combi boiler as well as output rates.

A combi boiler's flow rate (measured in litres per minute) describes how much water it can instantly heat then distribute to the taps and radiators in your home - you will need to factor this into your decision on a new combi boiler. This Worcester Bosch Greenstar 4000 25kW Combi boiler's flow rate is 9 L/m.

If you have a lot of radiators and bathrooms in your home and there's lots of demand within your household for hot water at the same time (like morning or evening showers and baths), you'll need a boiler with a high flow rate.

However, it's not quite that simple. If your local mains water pressure is low, you're not going to gain any benefit from choosing a combi boiler with a high flow rate because that higher flow rate 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.


Where will the Worcester Bosch Greenstar 4000 25kW fit in my house?

The Worcester Bosch Greenstar 4000 25kW measures 724 mm tall, 400 mm wide, and 310 mm deep.

Worcester Bosch Greenstar 4000 25kW – non-condensing or condensing?

How energy efficient is the Worcester Bosch Greenstar 4000 25kW combi?

The effects of climate change on the environment are leading many homeowners to question the damage they might be doing by the way they heat their homes.

Central heating accounts for 14% of greenhouse gas emissions in the UK. In larger British cities, gas boilers emit dangerous levels of nitrogen dioxide into the atmosphere.

Would choosing a Worcester Bosch Greenstar 4000 25kW combi help in the fight against climate change? What do the performance statistics suggest?

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 4000 25kW was awarded an efficiency rating of "94%", equivalent to a "A" rating on the SEDBUK system.

In 2015, new legislation was introduced by the EU to encourage manufacturers to develop more energy-efficient products that emit fewer harmful gases throughout their lifetime.

The Energy Related Products Directive (ERP) applies to all products that consume energy, including during the manufacturing process, at the point of final disposal, and all points in between.

The ERP rating of the Worcester Bosch Greenstar 4000 25kW is "A" for heat and "A" for hot water.

Does a Worcester Bosch Greenstar 4000 25kW combi boiler come with a warranty period?

A parts and labour warranty of 7 years is included with the Worcester Bosch Worcester Bosch Greenstar 4000 25kW boiler.


Worcester Bosch Greenstar 4000 25kW Gas Combi boiler specifications

Powered by GasGas
LocationExternal
Efficiency rating94%
Band ratingA
P/L Warranty7 Years
Output in kW25 kW
Height724 mm
Width400 mm
Depth310 mm
MountingWall
Flow rate9 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 4000 25kW boiler

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Worcester Bosch Greenstar 4000 25kW Combi Gas boiler

  1. Home
  2. Worcester Bosch Greenstar 4000 25kW
Plumbproud rating for this boiler
91.41%

Based on a wide-ranging set of important factors including the cost to install the boiler, its energy efficiency rating, running costs, and so on, this Worcester Bosch Greenstar 4000 25kW Combi boiler receives a score of 91.41% on our PlumbProud quality scoring system.

On most non-complicated installations, we would expect this Worcester Bosch Greenstar 4000 25kW Combi boiler to cost £2,100 including installation if you choose PlumbProud to do the work.

Wondering if the Worcester Bosch Greenstar 4000 25kW is the right boiler for your home? Then speak to a professional here by getting in touch via email or call us on 01604 343053. You can also get a free quote by entering your postcode in the box on the page.


Installed price guideline
£2,100

Get your free quote

Worcester Bosch Greenstar 4000 25kW Gas Combi boiler specifications

Powered by GasGas
LocationExternal
Efficiency rating94%
Band ratingA
P/L Warranty7 Years
Output in kW25 kW
Height724 mm
Width400 mm
Depth310 mm
MountingWall
Flow rate9 L/m
ERP HeatA
ERP WaterA

Worcester Bosch Greenstar 4000 25kW Combi Gas boiler frequently asked questions

Worcester Bosch Greenstar 4000 25kW - combi, system or regular boiler?

The Worcester Bosch Greenstar 4000 25kW is a combi boiler you may wish to consider if you want this type of 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 4000 25kW combi boiler the right choice 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 4000 25kW combi outputs at a maximum of 25 kW, so which types of property would this Worcester Bosch Greenstar 4000 25kW Combi boiler be appropriate for?

A heating engineer would recommend that the Worcester Bosch Greenstar 4000 25kW combi boiler would be a suitable installation option for smaller homes and apartments with up to 10 radiators and one bathroom.

With combi boilers, you need to consider the flow rate as well as the output rate. The flow rate (shown in litres per minute) measures how much water your boiler can draw from the mains which it then instantly heats and distributes to your taps and radiators.

However, a high flow rate is of little to no value if your local water pressure is low. If your local mains water pressure is 10l/m and your flow rate is 12l/m, your boiler will only be able to process 10l/m.

If you live in an area with high water pressure but your household has multiple bathrooms and/or radiators and many members of your household want to use hot water at the same time (like morning or evening baths or showers), it's unlikely that you'll be able to find a combi with a high enough flow rate.

As an indication, a power shower needs about 10 litres of water per minute, whereas the flow rate of this Worcester Bosch Greenstar 4000 25kW Combi boiler is 9 L/ml/m.

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 4000 25kW size

The Worcester Bosch Greenstar 4000 25kW has the following dimensions - 724 mm high, 400 mm wide, and 310 mm deep.

Is the Worcester Bosch Greenstar 4000 25kW a condensing or non-condensing boiler?

Is the Worcester Bosch Greenstar 4000 25kW combi boiler rated as environmentally friendly?

Environmentally-friendly heating has become an important issue for homeowners concerned about the accelerating pace of climate change.

In the largest cities of Britain, gas boilers are responsible for dangerous levels of atmospheric nitrogen dioxide emissions. In total, 14% of the UK’s greenhouse gases are produced by central heating systems.

Will choosing to install a Worcester Bosch Greenstar 4000 25kW combi in your home help the environment? Let's review 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 4000 25kW was rated at 94% with a SEDBUK grading of "A".

The Energy Related Products Directive (ERP) is European legislation that applies to all products which use or consume energy during their lifespan, including during the manufacturing process and when they're in actual use, right through to the point of final disposal.

The aim is to encourage manufacturers to create new products that are kinder to the environment and create fewer harmful gas emissions.

The Worcester Bosch Greenstar 4000 25kW has an ERP Heat rating of "A" and an ERP Water rating of "A".

How many years does the warranty period cover on a Worcester Bosch Greenstar 4000 25kW boiler?

The parts and labour warranty offered with this Worcester Bosch Greenstar 4000 25kW Combi boiler covers you for 7 years.


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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