
Are you looking for a quality, wall-hung boiler that can deliver fantastic flow rates to your large Edinburgh property?
Then the Worcester Bosch 42cdi classic may be the perfect choice for you – but just to make sure, I’ve done all the hard work by reviewing it in full!
So, let’s take a closer look at the 42cdi classic below:
Introduction
Having won ‘Which Best Buy’ four years running, it’s easy to see why so many of my customers prefer Worcester Bosch over any other brand.
The Worcester Bosch 42cdi classic features one of the highest hot water outputs available from a wall-hung boiler, which is why I personally recommend it.
It’s particularly ideal if you want to get rid of your large old boiler and associated tanks, whilst still benefitting from a great hot water output for high pressure showers.
Output and flow rate
With a heating output of 30kw, it will happily heat your large Edinburgh property without a hitch, although what you’re really buying this boiler for is the fantastic hot water output of 42kw.
You’ll find the 42cdi classic can supply 17.1 litres of hot water per minute to your taps, which is perfect if you like a high pressure shower or have two bathrooms or an en-suite. It can easily run a bath and a shower at the same time.
However, before making your final decision, I always recommend you have your chosen engineer check the incoming mains pressure. If there is not enough water coming into your home, you simply won’t benefit from the fantastic flow rates this boiler can provide.
TIP: Because this is such a large output boiler, your gas (fuel supply) pipe may have to be upgraded to 28mm, which will often involve lifting floorboards etc.
Size and extra features
This is a slightly larger all-hung boiler, so it won’t fit in your kitchen cupboard or Edinburgh press, unlike the compact range. The 42cdi classic’s dimensions are: 760 x 440 x 360, and because of its minimalist style, you’ll find it looks right at home on your kitchen wall or in a larger storage cupboard.
This particular boiler also has a wide choice of energy efficient controls, so you have benefit from even more savings on your heating bills.
Guarantee
The Worcester Bosch 42cdi classic comes with Worcester Bosch’s best no quibble 10-year boiler guarantee when fitted with Worcester Bosch Greenstar filter and comfort controls – which are also covered for 10 years. It’s actually one of the reasons I recommend this particular brand to all my customers.
You may find other boiler companies offering slightly longer guarantees for very similar spec models, but sometimes these things look too good to be true – and they often are. There’s usually a catch in the small print, or extra credit card charges before they’ll even agree to a call-out, so beware.
Tech specs
I’ve put together a quick summary of all you need to know about the Worcester Bosch Greenstar 42cdi classic, below:
- Heating output: 30kw
- Hot water output: 42kw (17.1 litres per minute)
- Ideal for: A large home with 2 showers, or a bath and shower.
- ERP rating: A, 90.2% efficiency
- Guarantee:10 years on boiler (when fitted with controls and filter)
Conclusion
If you need a wall-hung boiler to provide superb heating and flow rates to your large Edinburgh property, the Worcester Bosch 42cdi classic is a great choice.
This high-spec boiler with its 30kw heating output and 42kw hot water output means that you can benefit from all the heating and hot water your home could ever need, for optimum comfort.
Just ensure your home has sufficient incoming mains pressure – it’s also possible your chosen engineer will have to upgrade your gas pipe to 28mm due to the particularly high output of this boiler.
Last but not least, the no quibble 10-year boiler guarantee (when fitted with Worcester Bosch filter and controls) will see you through any difficulties.

I had one of these put in in September, meter pressure is 21 bar gas pipe has been done at 28mm but engineer can only get 14mb pressure at the boiler under working pressure. WB say it needs a bigger meter but SGN say the gas KW output is fine for the boiler. Gas engineer says the 28mm supply is fine. Don’t know where to go from here now, any ideas?
Thank you ffor this very useful appraisal.