Worcester Bosch Boiler Review – Greenstar CDi Classic, Combi System Heat
The Greenstar CDi Classic combi boiler is a top-range Worcester Bosch unit, although not quite their most powerful system. The manufacturer rates this system for homes with up to two bathrooms, and, notably, it has the highest hot water flow of the Greenstar combi line.
This review focuses exclusively on the combi version of the CDi Classic, which is also available in the system and regular boiler versions.
Greenstar CDi Classic Combi Boiler Information
This boiler is available in four models: the 29CDi, the 34CDi, the 38CDi, and the 42CDi. Each of these units is the same size at 760 x 440 x 360, so there are no concerns about size versus power to worry about.
Unfortunately, despite being a higher-end system, the Greenstar CDi Classic combi unit is not compatible with solar power systems and must run independently.
Since all four models provide the same central heating output of 30kW, the main distinguishing feature is their hot water flow rate. This goes from 11l/min on the 29CDi to 15l/min for the 42CDi, which is a decent increase between the minimum and maximum units.
That said, I do wish this difference was larger. There's a point with boilers where you could pay a lot more money for what's a relatively small change in flow rate when you get right down to it, and these diminishing returns can make it harder to justify getting a better model.
Other features of this unit include a temperature display, boiler control knobs, built-in frost protection for garage and loft installations, and a keyless filling link to make refilling easier.
Views and Reviews
The toughest part of reviewing boilers is getting adequate information about them. Manufacturers are happy to highlight features, but in many cases, only years of experience can show how good a system really is. I can’t spend years testing every boiler individually, but I can get information from other sources, and that's exactly what I did.
When I checked, Boilers Reviews gave this unit a total of 3.7/5 after three reviews. The reviewers on this site generally like the unit itself, but two of them noted that a Wi-Fi programming device available to them was extraordinarily difficult and frustrating to use, which brought down their overall view of the system.
I think this is an important point. If you're buying an advanced combi boiler with wireless controls and advanced programming systems, those need to function properly. Otherwise, you're not getting the unit you're paying for, so you might as well use a cheaper model instead.
That said, these reviews were from 2014 and 2016, and Worcester Bosch may have modified and updated its Wi-Fi programmer since these reviews were written. I couldn't find any information to say for sure, so keep this detail in mind if you're still interested in the CDi Classic.
Unfortunately, I could not find too many other independent reviews on this model. Many "reviews" are more like advertisements from companies that want to sell installations to you, and these aren't as useful as comments from actual buyers or technicians who have no financial stake in selling products.
For a broader view of these products, I decided to look at the Trustpilot score for Worcester Bosch. At the time of this review in late 2019, they had an overall rating of 4.7/5, with more than 13,000 reviews contributing to this.
Note that this score does not reflect the performance or value of the Greenstar CDi Classic as an individual boiler. However, it does provide some useful context and provide information about the company as a whole, which is almost as useful.
When I looked, 80% of reviews were Excellent (the highest score on Trustpilot), which is essentially the same as saying that one in five people had some sort of issue with their experience. These aren't necessarily awful issues since more than half of the remaining reviews are still positive, but there is a realistic chance of something going wrong during the installation or use of a boiler system.
While there are no perfectly foolproof methods to stop issues, having the installation and servicing done by trained, reputable individuals can at least help stop most problems before they occur.
Notably, many of the negative reviews on Trustpilot (6% of the review total) mentioned issues with getting service for faulty units.
If you simply can't be without hot water for more than a day or so, consider finding several reputable technicians now and keeping their contact information somewhere near your boiler in case you need to call them instead of Worcester Bosch. This isn't the cheapest option, but it may be necessary.
Final Thoughts
Overall, I think the Greenstar CDi Classic boiler is a decent unit, though I'm going to stop short of giving it my wholehearted recommendation. The main problem that I see is the problem with its advanced features that several reviewers mentioned.
As I said above, there's really no point in getting a feature-heavy boiler if those features are hard to use. Consider talking to an installer or company representative and asking them if they've improved on their wireless controller and programming options. Otherwise, hold off on this unit and look for a better value instead.
