Is the Worcester Bosch Greenstar CDi Compact 28 boiler a combi, system or regular boiler?

If you want a combi boiler for your flat or house, the Worcester Bosch Greenstar CDi Compact 28 might be an option for you to consider.

In older British homes, traditional boilers required you to find room for one or more storage tanks. One tank would keep hot water warm and the other stored cold water for later heating. Manufacturers introduced combi boilers to the UK in the 1970s so that homeowners could get the warmth and hot water they needed without having to sacrifice too much valuable space – remember that residential property in this country is among the smallest in the Western world.

Combi boilers deliver hot water to your radiators and taps using water they draw directly from the mains supply. As mains water travels through a combi boiler, the technology within it heats the cold water instantly and on demand. The hot water is then distributed throughout your house.

Combi boilers have one drawback, however: they can only heat a certain amount of water within a given time. For example, if someone uses the shower and another person uses the hot water tap at the same time, water pressure drops because water reaches each point differently.

Would the Worcester Bosch Greenstar CDi Compact 28 combi boiler be suitable for my house or flat?

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

This Worcester Bosch Greenstar CDi Compact 28 Combi boiler gets its power from gas and the power it's capable of producing is measured in kilowatts - the output rate is actually a kilowatt rate. The higher the output rate, the more kilowatts a boiler can use when heating water.

If you choose a boiler whose output rate is too low, it may not have enough power to make your water as hot as you would like. If you choose a boiler whose output rate is too high, you won't have to put up with lukewarm water but you will face higher gas bills.

The Worcester Bosch Greenstar CDi Compact 28 combi boiler has an output level of 28 kW, so which types of property would it be appropriate for?

A PlumbProud heating engineer would likely recommend that this Worcester Bosch Greenstar CDi Compact 28 Combi boiler is suitable for medium-sized homes and larger apartments with 10-15 radiators and two bathrooms.

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 CDi Compact 28 Combi boiler's flow rate is 11 L/m.

Like all combi boilers, the Worcester Bosch Greenstar CDi Compact 28 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 size is the Worcester Bosch Greenstar CDi Compact 28 boiler?

The Worcester Bosch Greenstar CDi Compact 28 boiler measures 680 mm [H] x 390 mm [W] x 280 mm [D] in size.

Greenstar CDi Compact 28 – condensing or non-condensing?

The Worcester Bosch Greenstar CDi Compact 28 is a condensing gas boiler - this is the type of boiler we recommend to most clients because they're better for the environment and they will save money on annual fuel bills.

A condensing boiler captures and recycles the warmth still present in both the flue exhaust gases and water vapour condensation created when gas is burned to provide your boiler with power.

This means it needs less gas to operate and it uses this extra energy to perform a number of tasks, including heating the colder water that comes back to the boiler from the radiators in your home.

Is the Worcester Bosch Greenstar CDi Compact 28 combi boiler an environmentally friendly choice?

Many homeowners are becoming increasingly concerned about how they heat their homes and the impact it has on climate change and other important environmental issues.

Central heating creates 14% of the UK’s greenhouse gases. And in Britain's larger cities, gas boilers are responsible for dangerous levels of nitrogen dioxide emissions.

If you decide to install a Worcester Bosch Greenstar CDi Compact 28 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 CDi Compact 28 was awarded an efficiency rating of 90.5% with a SEDBUK band rating of "A".

All products that consume energy throughout their lifespan must comply with the Energy Related Products (ERP) Directive.

Companies are legally obliged to reduce harmful gas emissions at all stages of a product's life cycle, from initial manufacturing right through to final disposal as well as when the product is in actual use.

The Worcester Bosch Greenstar CDi Compact 28 scores "A" for heat and "A" for water.

How long is the warranty offered by the manufacturer for the Worcester Bosch Greenstar CDi Compact 28 boiler?

The Worcester Bosch Greenstar CDi Compact 28 is supplied with a parts and labour warranty of 7 years.