Worcester Bosch Greenstar Classic 34CDi Combi Boiler Review

James Elston
Written by James Elston
Updated on 19th September 2023
Posted on 18th September 2023
Worcester Bosch Greenstar Classic 34CDi Combi Boiler Review

Worcester Bosch Greenstar 34CDi Classic combi boiler review, prices & installation costs

Today, we’re bringing you an in-depth Worcester Bosch Greenstar 34CDi Classic Combi Boiler review.

This is yet another offering in the very impressive Greenstar range from Worcester Bosch. They make some of the best combi boilers and best system boilers on the market. So, let’s see how good this one is.

The Worcester boiler range varies on price, but the Greenstar 34CDi classic price is around £2,300 to £2,600.

Feel free to check out our other reviews if you want to see how the other Greenstar boilers stack up against this one!

If you are thinking to yourself, What size Worcester boiler do I need? You can use our boiler calculator here.

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For now, our focus is solely on the 34CDi classic combi.

The Worcester Bosch 34CDi classic combi boiler is part of the manufacturing group that we instantly have a lot of confidence in because they have been around for such a long period of time within the UK.

Worcester Bosch Greenstar Classic 34CDi Combi Boiler Review

Those of you that have done your research will know that this is a big company in the boiler replacement industry.

They’ve won awards for their products, and most people will testify that this brand is trustworthy and reliable.

So, with that in mind, what’s so great about the Worcester Bosch Greenstar 34CDi Classic Combi Boiler?

Well, other than new boiler cost, here’s what we found out during our review:


The Worcester Bosch Greenstar 34CDi Classic Combi Boiler Worcester Bosch Greenstar Classic 34CDi Combi Boiler Review

When you first lay your eyes on this Worcester Bosch 34CDi combi boiler, you’re instantly drawn to the size.

It’s different from some of the other options in the Greenstar Range – like the 36CDi and 28CDi, which are both compacts.

This is a classic combi boiler, so it won’t fit in a standard kitchen cabinet but can be wall-mounted. The boiler installation would need to be done by a Gas Safe heating engineer.

The upside of the size is that it generates lots of power. You have a central heating output of 30kW, which lets you heat up to around 20 radiators.

If you think most houses have one, maybe two, radiators per room, then it easily provides enough power for a large family home.

The hot water output sits at 34kW, with a 12 litres per minute flow rate. Again, this means it meets the demands of medium-large sized family homes with up to two bathrooms.

If you can find the space to install this boiler, then it definitely offers some excellent performance stats.

You won’t worry about losing hot water or having a cold home during the winter with this classic range of the heating system, that’s for sure!

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Energy Efficiency Worcester Bosch Greenstar Classic 34CDi Combi Boiler Review

When you have a best combi boiler that’s so powerful, your next thoughts turn to efficiency.

How does the Greenstar 34CDi stand up in the ErP ratings?

For context, the ErP ratings are used to see how energy-efficient products are. All these types of boilers are condensing boilers too to make them super-efficient. 

They’re tested and trialled before going on sale, and each product gets slapped with a grade.

Here, you get an ErP rating A, with 92% energy efficiency. Those of you that have read our other Greenstar reviews will know that this is the standard across the range.

In effect, you have a powerful boiler that knows how to maximise all of the energy it produces.

By opting for a new boiler with a high energy rating, you will save money on the energy bills.

It basically means that the Worcester Bosch 34CDi classic can heat your radiators and hot water without calling upon too much energy.

Therefore, your monthly bills can decrease compared to if you used a less efficient boiler.

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Greenstar 34 CDi Usability Worcester Bosch Greenstar Classic 34CDi Combi Boiler Review

How easy is it to use the Greenstar 34CDi from Worcester Bosch?

Or, more to the point, how detailed are the controls such as the Worcester Bosch boiler temperature settings?

Well, on the boiler itself, you have very standard controls.

There’s not a lot to be blown away with here; Worcester boiler thermostat, it’s got temperature settings, different modes, easy-to-use knobs, and warning lights.

Pretty normal stuff, but combi boilers also need to ensure that they have additional controls to make them compliant with the Boiler Plus regulations.

34CDi Modern Accessories:

In short, these regulations mean that combi boilers must have time and temperature controls that work correctly and provide the owner with more control over the boiler.

There are different ways to do this, but Worcester Bosch has made the 34CDi compatible with smart thermostats.

So, all the controls can be found in an app on your phone, and you can tweak so many different settings to improve energy efficiency further.

The Bosch EasyControl smart thermostat is highly recommended for this boiler. It links up to your mobile devices and lets you play around with the temperature in your rooms.

You can do this remotely, meaning you can turn your heating on or off from outside your house!

We think that the Greenstar 34CDi has everything you need in an easy-to-operate boiler.

The main controls are simple, but you gain access to more detailed settings through smart thermostats.

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Warranty Worcester Bosch Greenstar Classic 34CDi Combi Boiler Review

All of the Worcester Bosch boiler range will come with a warranty.

Worcester Bosch will give you a free 5-year standard warranty when you purchase the Greenstar 34CDi.

This means if any problems occur with your Worcester Bosch combi boiler, you will have the help of a Worcester accredited installer.

Worcester boiler cover only covers manufacturing faults and defects, so you may need to find another warranty that covers accidental damage – or extends the manufacturer’s warranty even further.

For something as expensive as a boiler, it’s always worth protecting it as much as you can. Getting the boiler cover will keep your warranty valid.


Boiler Size

Worcester Bosch Greenstar Classic 34CDi Combi Boiler Review

As we said earlier, this isn’t a compact boiler.

It measures up at a chunky 760x440x360mm.

It’s far from massive, but it’s not the type of boiler you can hide away in a small kitchen cabinet.

So, you really need to have some kind of designated area to install this in.

Our advice is to take these measurements and look around your home to see if there’s a suitable place for a Greenstar Cdi boiler of this size.

If you need help, then contact a Gas-Safe heating engineer to assist.

Our Verdict

After carrying out this Worcester Bosch Greenstar 34CDi Classic Combi Boiler review, we conclude that it is a fantastic product for certain homes.

The obvious highlights are the power output and energy efficiency. We also believe that it has some great controls and can be used with smart thermostats to boost its performance.

If you have a home with two bathrooms, multiple bedrooms, and up to twenty radiators, then it could be perfect for you.

The only slight drawback is the size.

If you want something more slender and compact, then think about some of the other products in the Greenstar or Worcester boiler range. They have plenty of types of boilers to choose from.

Of course, if your home has more than twenty radiators and you have three or more bathrooms, then you might need a more powerful boiler like the 42CDi Classic.

All in all, we were impressed with the Worcester Bosch Greenstar 34CDi and believe it definitely serves a purpose for the right kind of customer.

If you like the sound of this Worcester 34CDi classic, but the price sounded too high, don’t panic at Boiler Central we offer different finance options. We have great boiler deals running all year round and have some great cheap boilers for those on a budget. 

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Written by
James Elston
James Elston Director Of Boiler Central
Posted on: 18th September 2023

James Elston is our resident boiler replacement and heating expert here at Boiler Central. With over 20 years experience in the boiler installation industry, James ensures that he knows everything there is about our Gas Safe boiler installations, energy saving and home heating solutions. This can be from simply procuring the latest best combi boilers, to reviewing and ensuring that Boiler Central maintains the highest standards across our boiler installation company.

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