GET A COMPETITIVE QUOTE

Please enter your postcode below to get a free, no obligation, personalised quotation from PlumbProud

Worcester Bosch Greenstar Heatslave II 12/18 boiler

  1. Home
  2. Worcester Bosch Greenstar Heatslave II 12/18
Plumbproud rating

76.19%

Worcester Bosch Greenstar Heatslave II 12/18 Combi Oil boiler

On the PlumbProud quality scoring system, we rate this Worcester Bosch Greenstar Heatslave II 12/18 Combi boiler 76.19%. To determine our rating, we take lots of different factors into consideration from price installed to manufacturer guarantees, energy efficiency, likely cost of running, and more.

We would expect that, unless there are complications during fitting, this Worcester Bosch Greenstar Heatslave II 12/18 Combi boiler would cost £3,500 supplied and professionally installed through PlumbProud.

For professional advice on whether the Worcester Bosch Greenstar Heatslave II 12/18 is the right boiler for your home or to receive a free quotation, please call 01604 343053 to speak to our friendly team. You are also welcome to email us by clicking here or you can enter your postcode into the quotation box on this page.


Installed price around

£3,500

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 Heatslave II 12/18 Combi Oil boiler frequently asked questions

Is this Worcester Bosch Greenstar Heatslave II 12/18 boiler a combi, system or regular boiler?

If you’re looking for a combi boiler for your house or flat, then the Worcester Bosch Greenstar Heatslave II 12/18 is one you may wish to consider.

Traditional boilers have one or two tanks - one holds hot water to keep it warm and the other water for later heating. Because UK residential property is among some of the smallest in the world, manufacturers introduced combi boilers and the heat pumps that go in them in the 1970s to reduce the amount of space boilers needed to take up.

The hot water needed for your radiators and taps is available on demand when you have a combi boiler. Combi boilers use technology located within the boiler to heat cold water, which it draws from the mains, and to distribute hot water where it's needed around your home.

A combi boiler, however, has the disadvantage of a maximum capacity for the amount of water it can heat. The result is that if someone uses the shower while another uses a hot water tap simultaneously, the amount of water reaching each point falls, causing water pressure to drop.

Should I install a Worcester Bosch Greenstar Heatslave II 12/18 combi boiler in my home?

To determine that, we need to consider the size of the boiler. Size doesn't mean how big it is - it means how big its "output" is.

The output rate of a boiler tells you how much power it has available to it for heating the water that comes out of your taps and warms your radiators. A higher output rate means that your boiler has more power at its disposal.

You need to make sure you select a boiler with the right output rate. That's because, if your output rate is too high, then your boiler will have more power than it needs but it will cost too much to run. If the output rate is too low, your water may often not be hot enough.

The Worcester Bosch Greenstar Heatslave II 12/18 combi's output is 18 kW, so which types of property would this Worcester Bosch Greenstar Heatslave II 12/18 Combi boiler be appropriate for?

A PlumbProud Gas Safe engineer would recommend that the most suitable type of property for a Worcester Bosch Greenstar Heatslave II 12/18 combi would be smaller homes and apartments containing up to 10 radiators and providing hot water for one bathroom.

As well as the output rate, you need to consider "flow rate" when choosing a combi boiler.

The flow rate describes how much water a combi boiler can draw from the mains, instantly heat, and then send to your radiators. Flow rates are measured in litres per second and this Worcester Bosch Greenstar Heatslave II 12/18 Combi boiler's flow rate is 15 L/m.

The water in your mains pipe also has its own flow rate - normally between 10 and 12l/m in most parts of Britain. This means that, if you choose a combi boiler with a flow rate of 17l/m where local water pressure is 11lm, it won't actually process more water because of the slower flow rate of the mains.

In addition, larger households with more than one bathroom, multiple radiators, and where family members may want to use hot water at the same time (like morning showers) may actually need a boiler with a higher flow rate than either the boiler or the local mains pipe.

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.


Making space for the Worcester Bosch Greenstar Heatslave II 12/18

The Worcester Bosch Greenstar Heatslave II 12/18 is 855 mm [H] by 520 mm [W] by 600 mm [D] in size.

Hundreds of thousands of properties in the UK still have floor-standing boilers like the Worcester Bosch Greenstar Heatslave II 12/18 despite the fact that over the last 20 years more compact, wall-hung boilers have become the preference for most homeowners keen to free up space in their properties.

While it is possible to replace your existing floor-standing boiler with a wall-mounted boiler to free up space in your home, please bear in mind that much of the pipework might need replacing, which is over and above the cost of the boiler and its installation. This will be a significant one-off investment if you do decide to switch and while the savings on your oil bills will repay it eventually, this will take a few years.

Please also bear in mind that if you’re considering replacing your current standard or system boiler with the Worcester Bosch Greenstar Heatslave II 12/18, you will need to have your hot water cylinder and/or expansion tank removed.

For information and guidance on the best course of action, please contact PlumbProud and we’ll share our advice with you.

Is the Worcester Bosch Greenstar Heatslave II 12/18 non-condensing or condensing?

Condensing boilers like the Worcester Bosch Greenstar Heatslave II 12/18 improve energy efficiency and reduce your annual expenditure on oil.

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 Worcester Bosch Greenstar Heatslave II 12/18 combi environmentally friendly?

How we heat our homes has become a pressing issue of concern for many homeowners worried about climate change and the environmental impact of their personal choices.

Central heating produces 14% of all greenhouse gas emissions in the UK. Gas boilers in the larger cities emit dangerous levels of nitrogen dioxide.

Let's take a closer look at whether installing a Worcester Bosch Greenstar Heatslave II 12/18 combi would be a good choice for the environment.

Boilers manufactured or supplied to UK domestic properties must achieve a legal minimum energy efficiency rating of 92% (equivalent to a good "A" grade using the SEDBUK scale). Prior to this, the minimum was 88% (88% and 89% are a "B" SEDBUK grade and anything 90% or above is an "A" grade).

The energy efficiency rating of a boiler refers to the amount of energy it uses to perform its everyday functions as well as the amount of energy it wastes.

The Worcester Bosch Greenstar Heatslave II 12/18 has been given a rating of 90% for energy efficiency, equivalent to a SEDBUK "A" rating.

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 Heatslave II 12/18 has an ERP Heat rating of "A" and an ERP Water rating of "B".

What is the length of the warranty on the Worcester Bosch Greenstar Heatslave II 12/18?

The Worcester Bosch Greenstar Heatslave II 12/18 boiler has a warranty covering parts and labour costs for up to 2 years after installation.


Worcester Bosch Greenstar Heatslave II 12/18 Oil Combi boiler specifications

Powered by GasOil
LocationExternal
Condensing?Yes
Efficiency rating90%
Band ratingA
LPG Compatible?No
P/L Warranty2 Years
Output in kW18 kW
Height855 mm
Width520 mm
Depth600 mm
MountingFloor
Flow rate15 L/m
ERP HeatA
ERP WaterB

The top 10 rated Oil Combi boilers

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

1Worcester Bosch Greenstar Heatslave II 12/1876.19%
2Worcester Bosch Greenstar Heatslave II 18/2576.12%
3Worcester Bosch Greenstar Heatslave II External 12/1875.95%
4Worcester Bosch Greenstar Heatslave II 25/3275.83%
5Worcester Bosch Greenstar Heatslave II External 25/3275.58%
6Grant Vortex Pro 2167.46%
7Grant Vortex Pro 2667.43%
8Grant Vortex Pro 26kW67.35%
9Grant Vortex Pro 2167.31%
10Grant Vortex Pro 2667.14%

Combi boilers

Choose from the UK’s biggest range of combis

Heat only boilers

The ideal boiler perfect for the largest homes

System boilers

Ideal for 3+ bedroom, 2+ bathroom homes

Boiler quote

Free, no obligation quote from our engineer

Worcester Bosch Greenstar Heatslave II 12/18 boiler

We will not be beaten on price -
ask us about our PRICE GUARANTEE!

Worcester Bosch Greenstar Heatslave II 12/18 Combi Oil boiler

  1. Home
  2. Worcester Bosch Greenstar Heatslave II 12/18
Plumbproud rating for this boiler
76.19%

We have rated this Worcester Bosch Greenstar Heatslave II 12/18 Combi boiler at 76.19% using the PlumbProud quality scoring system. To determine a rating, we weigh up a number of important considerations including the energy efficiency, estimated running costs, manufacturer's warranty, price of the boiler and more.

This Worcester Bosch Greenstar Heatslave II 12/18 Combi boiler will cost approximately £3,500 supplied and fully installed through PlumbProud assuming that there are no unexpected complications during the fitting.

Get a better understanding of installation costs for the Worcester Bosch Greenstar Heatslave II 12/18 by entering your postcode in the box supplied on this page. You can also call our professional team with any boiler-related queries on 01604 343053. Alternatively, please click here to email us.


Installed price guideline
£3,500

Get your free quote

Worcester Bosch Greenstar Heatslave II 12/18 Oil Combi boiler specifications

Powered by GasOil
LocationExternal
Condensing?Yes
Efficiency rating90%
Band ratingA
LPG Compatible?No
P/L Warranty2 Years
Output in kW18 kW
Height855 mm
Width520 mm
Depth600 mm
MountingFloor
Flow rate15 L/m
ERP HeatA
ERP WaterB

Worcester Bosch Greenstar Heatslave II 12/18 Combi Oil boiler frequently asked questions

Is the Worcester Bosch Greenstar Heatslave II 12/18 a standard, combi or system boiler?

When looking for a combi boiler for your house or flat, the Worcester Bosch Greenstar Heatslave II 12/18 might be a suitable option for you.

Traditional boilers require at least one large cylindrical tank to work, normally housed in a large landing cupboard, utility room or the attic. As the UK has some of the world's smallest residential properties, manufacturers introduced the combi boiler in the 1970s to address the issue of space while meeting homeowners' need for central heating and hot water at the same time.

Combi boilers don't need external storage tanks. Instead, they draw water directly from the mains, heat it and then distribute it on demand to the areas where it is needed.

The most important disadvantage of combi boilers is that they have a maximum capacity for the amount of water they can heat up. This means that, if one person in your household is having a shower and another person turns on a hot water tap elsewhere, then the volume, pressure and temperature of the water to both points decreases.

Would the Worcester Bosch Greenstar Heatslave II 12/18 combi boiler be suitable for my house or flat?

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 oil than you need to.

The Worcester Bosch Greenstar Heatslave II 12/18 combi has an output of 18 kW, so which types of property would this Worcester Bosch Greenstar Heatslave II 12/18 Combi boiler be appropriate for?

Most experienced boiler engineers would recommend this Worcester Bosch Greenstar Heatslave II 12/18 Combi boiler as a suitable option for smaller homes and apartments with no more than 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 Heatslave II 12/18 Combi boiler's flow rate is 15 L/m.

Like all combi boilers, the Worcester Bosch Greenstar Heatslave II 12/18 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.


What are the dimensions of the Worcester Bosch Greenstar Heatslave II 12/18 boiler?

The Worcester Bosch Greenstar Heatslave II 12/18 boiler is 855 mm high, 520 mm wide, and 600 mm deep.

Wall-hung boilers have become the preferred choice for homeowners in the UK over the last 20 years, but hundreds of thousands of homes still use bulkier floor-standing models for their central heating. It is possible to replace your floor-standing boiler with a wall-mounted one if you wish so that you and your family have more living space. But we must advise you that you may also have to pay to replace some or all of your existing pipework.

You should however be able to recoup this cost in full after a few years because of the savings you make each quarter on your oil bills.

If you do replace a heat only or system boiler with the Worcester Bosch Greenstar Heatslave II 12/18, then you'll also need to budget for removing your hot water cylinder/expansion tank.

If you’re not sure what the right step is for you, please contact PlumbProud today.

Worcester Bosch Greenstar Heatslave II 12/18 – condensing or non-condensing?

The Worcester Bosch Greenstar Heatslave II 12/18 boiler is a condensing oil boiler and we recommend that you select one of the latest models if possible.

Condensing boilers reduce homeowners' oil bills and are better for the environment. They do this by capturing and recycling the heat still present in the flue exhaust gases and water vapour condensation produced when boilers burn oil to generate the power they need to operate.

Is the Worcester Bosch Greenstar Heatslave II 12/18 combi boiler an environmentally friendly choice?

With more and more people concerned about climate change, how we heat our homes and the damage it does to the environment is increasingly being questioned by British homeowners.

The heating of our homes accounts for 14% of the UK's greenhouse gas emissions. Especially in the big cities, gas boilers are responsible for dangerous levels of nitrogen dioxide emissions.

Do the figures suggest that installing the Worcester Bosch Greenstar Heatslave II 12/18 combi at your property would help in the fight against climate change?

All boilers manufactured and installed in the UK are required by law to have an energy efficiency rating of at least 92%, equivalent to a good “A” rating on the SEDBUK scale. Before this, the minimum was 88% (ratings of 88% and 89% are equivalent to a high “B” SEDBUK rating and anything 90% or higher is an "A" rating).

A boiler's energy efficiency rating is designed to let you know how much energy is used and wasted during normal functioning.

The Worcester Bosch Greenstar Heatslave II 12/18 was given an efficiency rating of 90% and a band rating of "A".

The Energy Related Products Directive, also known as ERP, is European legislation that intends to reduce energy consumption related to products right from the initial manufacturing process through to eventual final disposal.

The purpose of the directive is to encourage manufacturers to create new products that are kinder to the environment and which result in lower overall harmful gas emissions through a product's entire life cycle.

The Worcester Bosch Greenstar Heatslave II 12/18 has a rating of "A" for heat and "B" for water.

How long am I covered by the warranty for if the Worcester Bosch Greenstar Heatslave II 12/18 breaks down?

The Worcester Bosch Greenstar Heatslave II 12/18 boiler has a warranty covering parts and labour costs for up to 2 years after installation.


The top 10 rated Oil Combi boilers

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

1Worcester Bosch Greenstar Heatslave II 12/1876.19%
2Worcester Bosch Greenstar Heatslave II 18/2576.12%
3Worcester Bosch Greenstar Heatslave II External 12/1875.95%
4Worcester Bosch Greenstar Heatslave II 25/3275.83%
5Worcester Bosch Greenstar Heatslave II External 25/3275.58%
6Grant Vortex Pro 2167.46%
7Grant Vortex Pro 2667.43%
8Grant Vortex Pro 26kW67.35%
9Grant Vortex Pro 2167.31%
10Grant Vortex Pro 2667.14%
Menu