Are you looking for the best Worcester Bosch combi boiler for your average-sized household?
If so, you’ve probably been looking over the Worcester Bosch Greenstar 28cdi, 30i and 30si. But wait a minute… what’s the difference?
As an experienced Worcester Bosch accredited engineer, I hear all the time how similar these boilers are. However, they do have their differences.
Let me go over everything you need to know, so you can make the most informed choice.
Output and flow rate
In terms of heating output, all three of these boilers offer the same 24kW to your radiators. This is idea for a small to average-sized property, with average-sized rooms. I know that doesn’t help much when trying to distinguish which is best!
However, things start to differ a bit when we get to the flow rates. At 28kW, the 28cdi has the lowest flow rate of the lot, only provided 11.5 litres to your taps. This is in comparison to the 12.3 litres per minute that the 30i and 30si boilers both supply, with an output of 30kW to the hot water.
These two are probably better suited if you want to be taking a lot of baths, as you’ll really notice the difference.
Size and special features
Measuring in at just 690mm x 390mm x 280mm, the 28cdi and 30si compact live up to their name and is small enough to comfortably fit inside a standard kitchen cupboard or Edinburgh press cupboard – great if space is a premium in your home!
Despite these boilers being compact, the controls and key components are positioned in such a way that they’re still easy to work on. Which is why they get the engineers’ vote!
The Worcester Bosch 30i is a bit bigger, and ,measuring in at 710mm x 400mm x 330mm, isn’t compact. This means it won’t fit in a standard kitchen cupboard. Instead, it’d need to be wall-mounted, or fitted in a larger cupboard.
Guarantee
Finally, Worcester Bosch have a great, no-quibble guarantee. It’s actually one of the best on the market right now! However, only the 28cdi will cover you for a full 10 years when fitted with Worcester Bosch controls and filter by an accredited engineer.
In contrast, the Worcester Bosch 30i offers an 8-year guarantee, whereas you can get 9 years out of the 30si compact. It may not seem like a lot of difference, but if you want ultimate peace of mind, the 28cdi wins out.
Tech specs compared at a glance
Want to see how each of these boilers stand up against each other? Sometimes the best way to get a clearer picture is to compare all the technical stuff side-by-side. Which is exactly what I’ve done below!
The Worcester Bosch Greenstar 28cdi compact:
- Heating output: 24kw
- Hot water output: 28kw (11.5 litres per minute)
- Ideal for: Small property with average-sized rooms
- ERP rating: A
- Guarantee: 10 years*
*When fitted with own-brand filter and controls by an accredited engineer
The Worcester Bosch Greenstar 30i:
- Heating output: 24kw
- Hot water output: 30kw (12.3 litres per minute)
- Ideal for: A 2 – 3 bedroom house or apartment. This boiler will fill a bath and run a high pressure shower (just not at the same time)
- Guarantee: 8 years
- ERP rating: A
*When fitted with Worcester Bosch magnetic central heating filter, by a Worcester Bosch accredited installer
The Worcester Bosch Greenstar 30si compact:
- Heating output: 24kw
- Hot water output: 30kw (12.3 litres per minute)
- Ideal for: A 2 – 3 bedroom house or apartment. This boiler will fill a bath and run a high pressure shower (just not at the same time)
- ERP rating: A
- Guarantee: 9 years when fitted by an accredited installer, with Worcester Bosch’s own filter and controls
*When fitted with own-brand filter and controls by an accredited engineer
Advice from an experienced engineer
I’ve recently had two or three different customers tell me they were confused by how similar these boilers are. However, after some research, most have opted for the 28cdi with Worcester Bosch controls, filter and a 10-year guarantee.
So, if the guarantee if very important to you, and you feel the extra 0.8 litres of extra hot water per minute isn’t important, I’d go for the 28cdi. It’s perfect for homeowners who use the shower a lot, and the bath very little.
However, if you’re looking to fit the Hive, Nest or Tado, there’s little point in choosing the 28cdi compact over the other models, as you’ll only get an 8-year guarantee. Well, unless of course, you really need a compact model.
If a compact isn’t required, and price is a concern, my advice is to opt for the 30i. It’s the most popular of all the Worcester Bosch boilers, and for good reason. It does the job and can be ideal for most average households!
Conclusion
I hope this blog has given you a better understanding of how the Worcester Bosch Greenstar 28cdi compact stands up to its biggest rivals: the 30i and 30si compact! All of these models are Worcester Bosch, but there’ll all just that little bit different.
Do you have any other questions about the Worcester Bosch Greenstar 28cdi? Let me know in the comments. I promise to reply!
