Worcester Bosch is one of the most reliable and trusted boiler manufacturers and have an excellent reputation for manufacturing and engineering, and this hasn’t been lost on their condensing combi boiler range.

Worcester Bosch 42cdi Combi Boiler

The Worcester Bosch 42cdi is a powerful boiler that will suit a larger home as it can meet high demands for heat and hot water. Choosing this Worcester boiler will ensure you will have a highly efficient solution and the opportunity to get a comprehensive a 10 year guarantee.

Output and flow rate

This 42cdi provides 42kw to the hot water and only 30 kw to the heating circuit. So, that means it can easily run two showers at once, or a bath and shower simultaneously. It will also happily heat a 5-bedroom house with10-14 radiators.

Here’s a brief overview:

  • Heating output: 30 kw
  • Hot water output: 42 kw, with a flow rate of 17.1 litres per minute
  • Ideal for: A large five-bedroom home with 2 bathrooms, and 10-14 radiators
  • ERP rating:A
  • Guarantee: 10 years (when fitted with own-brand filter by an accredited installer)

Compare output and flow rate below

  • you’ll find the relevant central heating and hot water outputs for each of these boilers, as well as the flow rate you can expect to your taps:Greenstar 29CDi classic:This boiler provides an output of 30 kw to the heating and 30kwto the hot water at 12.3 litres of hot water per minute (35 degrees Celsius)
  • Greenstar 34CDi classic:This boiler will give you an output of 30 kw to the heating and 35 kw to the hot water at 14.3 litres of hot water per minute (35 degrees Celsius
  • Greenstar 38CDi classic:This boiler supplies an output of 30 kw to the heating and 40 kw to the hot water at 16.4 litres of hot water per minute (35 degrees Celsius)
  • Greenstar 42CDi classic: This boiler allows for an output of 30 kw to the heating and 42 kwto the hot water at 17.2 litres of hot water per minute (35 degrees Celsius)

    Advanced Features

    The boilers are wall hung and they can go onto your kitchen wall or in store cupboard but alas the Worcester Bosch classic range will not fit into a kitchen cupboard, as they measure 760mm x 440xx x 360mm but other Worcester boilers may well do so. This is best to check with your surveyor.

    Another great feature is include the ability to range-rate the CH output to perfectly match the home’s requirement.

    A great feature of the CDi classic is the large internal siphon which eliminates the risk of your condensate pipe freezing over, along with an in-built keyless filling link provided as standard. These boilers also come with advanced energy efficient controls.


    Worcester Bosch Greenstar CDi classic combi boiler comes highly recommended by 9 out of 10 heating engineers. If you feel like this powerful boiler will fulfil your requirements contact the office for a free survey and your surveyor will assess your home and your needs and ensure you get the right boiler installed into your home

worcester bosch logo
  • Excellent technology
  • Compact combi boiler
  • A rated – highest possible efficiency rating
  • Can not mount onto the wall
  • Easy to service removable side panels
  • Suited to a 3 to 5 bed 2 bath large home
  • Strong flow rate of 16.4 litres per minute
  • No water tank required.
  • Up to 10 years warranty
  • Excellent Which? reviews score of 75%

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