(Boiler-only price: comparing up to five suppliers, including Screwfix and Plumbase, where possible. Correct January 2024).
The Worcester Bosch Greenstar CDi Highflow boiler is a floor-standing unit. It is a powerful boiler that can provide up to 25 litres of hot water a minute. Perfect for large homes with multiple showers and hot taps in use simultaneously.
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The Worcester Bosch Greenstar CDi Highflow has been designed for homes with high hot water demand. To supply large amounts of hot water is quite large and heavy (over 100kg). It cannot be wall-mounted, instead it sits on the floor. Normally underneath a kitchen worktop.
Like most modern boilers Highflows can integrate with smart thermostats. Worcester Bosch does have their own EasyControl system.
The Highflow is part of the energy-efficient Greenstar range, which has won the Which? ‘Best Buy’ award multiple times
| Manufacturer | Worcester Bosch |
| Model | Greenstar CDi Highflow |
| Variations | 440CDi and 550CDi |
| Condensing | Yes |
| Efficiency Rating | 92% |
| Energy Efficiency Class | A Rated |
| LPG Compatible | Yes |
| Warranty | 10 years |
| Central Heating Max. Output | 29.2 or 30.6 kW |
| Hot Water Flow Rate | 20 and 25 litres/minute |
| Mounting | Floor standing |
| Weight | 112 kg |
| Dimensions | 850mm (Height) x 600 (Width) x 600mm (Depth) |
The Greenstar CDi Highflow boiler is designed for larger homes. It is a reliable boiler engineered to provide energy-efficient hot water and heating.
440CDi and 550CDi
The main difference between the two versions is the hot water flow rate. The 440 can produce 20 litres a minute, whilst the 550 can produce 25 litres of hot water per minute.
Very large and heavy
Like a washing machine or a dishwasher and a weight of over 100kg, this is a very large and heavy boiler. For this reason, it is a floor-standing boiler and won’t fit in a kitchen cupboard. Instead, it is more suited to being housed in a recess where a washing machine or a dishwasher could go.
A name you know
Worcester Bosch is a name you will know. The company has been offering boilers to the UK market since the 1960s. Throughout this time, they have developed an excellent reputation. However, it should be noted that the quality of some of their boilers is not what it once was.
Aluminium heat exchanger
Aluminium heat exchangers are not as good as stainless steel equivalents. They have good initial performance but they can lose 10% efficiency over 10 years. Aluminium heat exchangers are susceptible to rust and corrosion. This affects efficiency.
Some of these issues could be covered by the warranty. However, if the water in your heating system isn’t kept in good condition it could cause issue which are not covered. It’s also worth noting that any issues after the warranty period may be very expensive.
Accessibility
There can be issues with access depending on how the boilers are installed. This is because the boiler is so large. However, if it’s installed with ample space, the removable side panels provide access when the boiler requires servicing or repairs
Choose from a range of control options
With the CDi Highflow boilers, you can opt for the standard manual control panel featuring an LED display. You also have the option to install a complimentary smart heating system. Utilising smart technology, you can control heating remotely with apps on your phone.
Assembled in the UK
The Greenstar CDi Highflow is assembled in the Worcester Bosch production facility in Worcestershire. But, whilst it is assembled here, many of the parts are manufactured elsewhere by 3rd party companies.
Plastic parts
Many of the parts and components utilised within this boiler are made from plastic. These parts can fatigue easily over time causing issues. If serviced correctly every year, this may not be an issue, but often, boilers are not serviced correctly. We would recommend boilers with brass and copper internal components where possible.
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