Are you searching for the perfect direct replacement to the old regular boiler in your 3-4 bedroom Edinburgh home?

Many of my customers come to me when their old, regular boilers have packed up, but at the same time, they don’t always want the upheaval that comes with switching to a combi. That’s why I tell them the Worcester Bosch Greenstar ri range is an ideal solution.

I’ve put together this review so that you can learn more about the Worcester Bosch Greenstar 18ri, and make the best decision for your home.


Worcester Bosch has a reputation that is second-to-none, having won Which’s ‘Best Buy’ four years running, so you already know you’re onto a winner.

The Worcester Bosch Greenstar 18ri provides a quick fix if you’re looking for a direct replacement for your old, regular boiler, and can be installed in just 3-4 hours. So, all of your radiators, pipework and tank can just be left in, the boiler replaced and the system flushed out – simple as.

I’ve already covered the Worcester Bosch Greenstar 12ri (INSERT LINK) and 15ri (INSERT LINK), so you may have landed here if you’ve decided you need just that little bit extra power to the heating and hot water tank.

Output and flow rate

And with an output of 18kw, the 18ri certainly gives you what you’re looking for, with that added oomph to make sure you have all the heating and hot water you could possibly need for a small 3-4bedroom home with 6-8 radiators. Saying that, it’s still middle-of-the-line, so there’s always the option to size up to the 24ri model, or even the 30cdi.

If you’re unsure of what size boiler you need, get your engineer to take a look at your home to help determine the right output level for you – always better to be safe than sorry.

As I always say, this is a high efficiency condensing boiler, so it’s important to get your engineer to check your pipework is up to specification, as it is not compatible with gravity hot water. The 18ri has to be fitted with a fully pumped system.

Size and special features

The Worcester Bosch Greenstar 18ri is a compact boiler that will happily fit in your kitchen cupboard or Edinburgh press – perfect for making the most of the available space in your home.

Another great feature of this boiler is that it is compatible with solar heating – so it’s future-proof if it’s something you’re considering in the next 10 years.


This particular model comes with Worcester Bosch’s fantastic no quibble 8-year boiler guarantee, * so you’ll be covered for all eventualities.

I personally think Worcester Bosch currently has the best boiler guarantee on the market. It’s true that there are longer guarantees out there from other boiler companies, but there’s often a catch in the small print, or extra credit card charges before they’ll even agree to a call-out (Vaillant is one exception to this).

Tech specs

Below, I’ve summarised all the important info you need to know about the Worcester Bosch Greenstar 18ri:

  • Heating and hot water output: 18kw
  • Ideal for: A small 3-4 bedroom home with 6-8 radiators
  • ERP rating: A
  • Guarantee: 8 years *


So, there we have it – everything you need to know about the Worcester Bosch Greenstar 18ri. It’s a regular boiler, and is perfect if you’re looking for a quick fix to replace your old one – with minimal upheaval involved. Everyone’s happy!

The output of 18kw makes this boiler very middle-of-the-range, and is ideal for a 3-4 bedroom home with 6-8 radiators. However, if you have a large home with high ceilings and stone walls, you may be better off sizing up to the 24ri.

The 18ri is a compact model, so it’s very convenient for fitting in your kitchen cupboard or Edinburgh press – plus, it’s compatible with solar heating! Top it all off with Worcester Bosch’s fantastic no-quibble 8-year guarantee* and you’re laughing.

What do you think of the Worcester Bosch Greenstar 18ri?

8 year guarantee is when fitted with Worcester Greenstar filter and installed by Worcester Bosch accredited installer.