Are you in the market for a new Worcester Bosch Greenstar boiler?

If so, you may have heard the bestselling Worcester Bosch Greenstar 28i Junior has been discontinued – but no worries, as there’s an even better replacement on the scene!

I’ve had plenty experience of fitting Worcester Bosch boilers during my time as a heating engineer, and it’s a brand I still trust today. In fact, we’ve installed hundreds of these boilers now, and from our point of view you can fit them, commission them, and let them work away in the background for many years to come.

So, below, I’m going to tell you all about the new Worcester Bosch Greenstar 30i and why it could be your next combi boiler.

But first, let’s take a quick look back at the Greenstar 28i Junior.

Out with the old…

Worcester Bosch’s bestselling boiler, the 28i Junior models were made at the time to fit the exact requirements of most homeowners, and were suited to an apartment or small house. They could feed a high pressure shower without difficulty, and they also had no trouble filling a bath.

These boiler provided 24kw output to the heating circuit, and were generally reliable, well-made and easy to service. Parts were always (and still are) readily available and reasonably priced, and although this was a premium priced boiler, I always found over the whole of life cost, they won hands down.

It’s easy to see why the 28i Junior was a firm favourite – perhaps you even have one fitted in your home right now, and are in need of a replacement. Well, look no further…

Introducing the new Worcester Bosch Greenstar 30i

The latest Greenstar 30i (the direct replacement to the 28i Junior) was introduced so that Worcester Bosch fell in-line with the new ERP directive which was first introduced on the 26th September 2015.

Because of this, the new 30i is much more energy efficient, and meets all the new criteria and standards set in place, along with a new energy saving bulb, lower carbon emissions, and MUCH better flow rates!

From an engineer’s perspective, they are easy to work on and straightforward to install. We have replaced a few 28i Juniors to the new 30i models now, and all of our customers have been impressed with the higher flow rate of hot water.

So, let’s take a closer look at exactly what the Worcester Bosch Greenstar 30i has to offer, shall we?

Output and flow rate

The 30i provides a heating output of 24kw, but unlike the 28i Junior before it, this model can supply you with 12.3 litres of hot water per minute – in fact, that’s the whole reason Worcester Bosch upped the specifications from 28kw to 30kw!

As a heating engineer, I find these new specs really hit the mark, as everyone seems to want faster flow rates nowadays – after all, who enjoying having to wait half an hour to fill a bathtub?

Size and special features

Unfortunately, the Greenstar 30i combi is not a compact model, so you’ll find it won’t fit in your standard-sized kitchen cupboard. This boiler’s exact measurements are: 400mm wide, 700mm high, and 330mm deep.

TIP: However, if you do find you need a compact boiler for your kitchen, you can get around this by paying a little bit more to fit the Worcester Bosch Greenstar 30si, which is 390mm wide, 690mm high, and 280mm deep.

The good news about the 30i combi is that a flue can be fitted either vertically or horizontally, which is helpful if you need a couple of different options for where to fit your boiler.


You may be glad to hear the Worcester Bosch Greenstar 30i combi comes with the brand’s brilliant 8-year no-quibble guarantee, which means you’re covered for both parts and labour if any unforeseen circumstances occur – with dedicated engineers ready to attend call-outs if necessary.

This market-leading guarantee is one of the reasons I recommend Worcester Bosch to my customers, as not all manufacturers match up – you have to watch out for little clauses which mean you’re not fully covered, or unexpected credit card charges for call-outs!

TIP: Remember to arrange an annual service with a Gas Safe registered engineer, as this keeps your guarantee valid for the full term.

Tech specs

Here’s a brief overview of the exact specifications for the Greenstar 30i:

  • Heating output: 24 kw
  • Hot water output and flow rate: 30kw, with 12.3 litres per minute
  • Ideal for: A small house or apartment. This boiler will fill a bath and run a high pressure shower (just not at the same time)
  • Guarantee: 8 years (when fitted with Worcester Bosch magnetic central heating filter, by a Worcester Bosch accredited installer)
  • ERP rating: A


We were sad to say goodbye to the Worcester Bosch Greenstar 28i Junior, but if you want the perfect replacement that’s fully up-to-spec with the latest ERP regulations – plus much better flow rates – look no further than the Worcester Bosch Greenstar 30i combi boiler.

Do you have any questions about this particular model? Feel free to leave a comment below, or for any other boiler-related queries, get in touch with me directly. I’m here to help!